Slide 1

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 2

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 3

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 4

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 5

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 6

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 7

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 8

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 9

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 10

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 11

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 12

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 13

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 14

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 15

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 16

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 17

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 18

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 19

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 20

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 21

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 22

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 23

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 24

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 25

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 26

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 27

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 28

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 29

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 30

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 31

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 32

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 33

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 34

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 35

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix


Slide 36

Digestive System
Digestive Tract

Digestive System
Digestive
system

Digestive Tract: oral cavity, esophagus,

stomach, small and large
intestines, rectum, and anus.

Digestive glands:

salivary glands, liver,
gallbladder and pancreas.

Functions:
Food intake, preparation of food for swallowing
and digestion. Obtain the molecules necessary for
the maintenance, growth, and energy needs for the
body. Digestive tract is a protective barrier.

I. GENERAL STRUCTURE OF
THE DIGESTIVE TRACT
Epithelium

Mucosa

Lamina propria
Muscularis mucosae

Submucosa
Muscularis externa
Serosa or adventitia

Adventitia
Musculairs externa
Submucosa
Mucosa
Muscularis mucosae
Lamina propria

Epithelium

Myenteric plexus

Submucosa nerve plexus

Figure . Schematic structure of a portion of the digestive tract with
various components

A.Mucosa

Innermost and most important layer

1.Epithelium A barrier between the lumen of digestive
tract and the body
a. Simple columnar epithelium on most
part for absorption and secretion
b.Stratified squamous epithelium on both
ends is capable withstanding abrasion
2.Lamina propria

A layer of loose connective tissue
that is rich in capillaries, lymph
vessels & tissue, glands.

3.Muscularis thin layer smooth muscle fibers, its
mucosae contraction assist secration of minor glands.
Inner circular and outer longitudinal layer

B.Submucosa

Loose connective tissue, many blood , lymph vessels ,a
submucosa (Meissner’s) nerve plexus, submucosal glands
Mucosa and submucosa form projections into the lumen
to increase surface area.

C.Muscularis externa
smooth muscle fibers (except 2 ends) arranged in inner
circular and outer longitudinal layer,
myenteric(Auerbach’s) nerve plexus

D. Serosa or Adventitia

Outer most, LCT

1.serosa- covered with simple squamous epithelium,
lubricating surface and reducing friction
2. Adventitia- not covered with mesothelium

II. Esophagus
1.Epithelium: Stratified squamous epi
A. Mucosa 2.Lamina propria: Dense CT
3.Muscularis mucosae: smooth muscle
longitudinally arranged

B. Submucosa: Dense collagenous & elastic fibres
(Esophageal submucosal glands, BV,LV,NF)
the upper one third

C.Muscularis the middle third
the distal third

D. adventitia: LCT

Skeletal muscle
intermingal
smooth muscle

Esophageal mucosa

Esophageal submucosal glands

III. Stomach
1.epithelium: simple columnar epi. (VILLI)

Mucosa

2. lamina propria: glands, lymphoid tissue
3. muscularis muscosae: smooth
muscle

Submucosa
Muscularis
Serosa

Loose, areolar CT
three layer smooth muscle

Regions of the stomach and their histological structure.

Gastric Glands
The lamina proparia contains
numerous glands. Three types of
glands: cardiac and pyloric glands
located in the cardiac and pyloric
region, respectively, and both mainly
secrete mucus. Gastric or fundic
glands, located over the body and
fundus, consist of 5 types of cells.

A) Cardic Glands:
simple tubular or compound glands
cells are columnar in shape and
mostly mucus-secreting

B) Pyloric Glands:
Branched, convoluted glands
Secrete mucus, lysozyme and a
small quantity of proteolytic
enzyme.

c) Gastric (fundic) Glands
Consists of 5 types of cells
1.
2.
3.
4.
5.

Chief (zymogenic) cells- pepsinogen
Parietal (oxyntic cells)- HCL
Mucous neck Cells- mucus
Endocrine cells
Undifferentiated cells

Diagram of a chief cell
Apical microvilli
\

\

Diagram of a parietal cell

parietal cell

APUD (amine
precursor uptake
and
decarboxylation)
system and form
part of diffuse
neuroendocrine
system

IV Small Intestine
Small intestine is divided into 3 segments:
Duodenum
Jejunum
Ileum
The mucosa and sub mucosa of the small
intestine are arranged in permanent
circular folds (plicae circulares)

Mucosa
Mocosa lining of the small intestine is
characterised by the presence of a
dense mat of finger-like projection
known as villi (0.5-1.5mm in length)
Crypts or intestinal glands, which
almost extend to the muscularis
mucosa, open between the bases of
villi.

SMALL GUT PARTS
MUSCULAR smooth muscle

suspensory MESENTERY
with blood vessels

VILLI covered
with simple
columnar
epithelium
INTESTINAL
GLANDS

SUBMUCOSA
connective tissue

covering SEROSA
with mesothelium

Intestine glands (intestine crypts)

Epithelium- simple columnar epithelium
3 types of cells are found
1.
Absorptive cells
2.
Goblet cells
3.
Enteroendocrine cells
Lamina Propria – LCT with a large
cellular component
isolated lymphatic nodules
Peyer’s patches
Muscularis Mucosa
inner circular and outer longitudinal
smooth muscle layer

Submucosa- DCT and contains
duodenal glands in the duodenum
Muscularis Externa- inner circular and
outer longitudinal smooth muscle
layer
Serosa/adventitia- except for the
duodenum, which is retroperitoneal,
the rest of the small intestine has an
outer layer of serosa

V Large Intestine
The main function of the large
intestine, which includes the caecum,
appendix, colon, rectum and anal
canal ending as the anus, is
absorption of water and minerals.

Colon
The main features of colon are:
(a) An absence of plicae and villi
(b) An epithelium containing large
numbers of goblet cells.
(c) Well-developed, long, deep and
closely-packed intestinal crypts.
(d) The outer longitudinal layer of the
muscularis externa is organised into
three thick, longitudinal bands
(taeniae coli)

Large intestine

Appendix
The main characteristics of the appendix are:
(a) It is histologically similar to the colon but
has a thinner wall, smaller lumen and
fewer intestinal glands.
(b) It has lymphatic tissue masses in the
lamina propria and submucosa.
(c) The muscularis mucosae is incomplete
and very thin.

Appendix