Transcript MITOCHONDRIA

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TISSUES
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Cells Tissues Organs Organ systems Organism
Cells are not found by themselves; they’re with others. These
are called tissues.
TISSUE: A group of cells, usually similar, which share a particular
function.
ORGAN A group of tissues which share a particular function.
ORGAN SYSTEM: A group of organs which share a particular
function (digestive system, nervous system).
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Cell Differentiation
 Through the process of cell differentiation, each cell
develops a characteristic set of structural features.
 Each cell has to contribute one piece toward the overall
function of the organism, so that all the vital functions
can be covered.
 During differentiation, cells in nearby locations become
able to work together.
 After differentiation, cells do not change their function
throughout their life cycle
TYPES OF TISSUES WE’LL
DISCUSS:
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EPITHELIUM: a sheet of cells that makes up the surface
of the skin and also lines tubes in the body.
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CONNECTIVE TISSUE: deep to the epithelium; supplies
oxygen and nutrients to epithelium.
Fibrous (Proper) Connective Tissue
Special Connective Tissue (cartilage, bone, blood, muscles,
nerves)
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MUSCLE TISSUE: makes up muscles, and these cells are able
to contract, unlike fibrous connective tissue. It is bound
together by areolar connective tissue. (discussed in later
lectures)
NERVOUS TISSUE: makes up brain and nerves (discussed in
later lectures)
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EPITHELIA: (plural form of epithelium): a sheet of cells
that makes up the surface of the skin and also lines tubes in
the body.
Function of epithelia:
 The epithelial cells are the type of tissue that protects
the underlying structures
 What is the difference between epithelium and
epidermis?
 Epidermis is the outermost layer of skin. It consists of
epithelial cells, but epithelium is also found in areas
lining the tubes of the body (digestive, respiratory,
urinary systems, etc)
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Epithelium
 Epithelium is the tissue that covers the outside of the
body (the top layer of the skin), and it also lines the
tubes within the body.
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Digestive tract
Respiratory tract
Cardiovascular system
Urinary tract
Reproductive tract
Sweat glands and other exocrine glands
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Microvilli
 The presence of large numbers of microvilli on the
exposed surfaces of epithelial cells indicates that this is
the area where absorption and secretion take place.
 These cells are transportation specialists.
 They are probably located along portions of the
digestive and urinary tracts
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 The hollow space
within each of these
tubes is called a
lumen.
Kidney
 The lumens are
always lined by
epithelial cells.
Sweat
glands
Trachea
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Basement Membrane
 All epithelia sit on top of connective tissue, and is
connected to it by a BASEMENT MEMBRANE (which is
not a cell membrane), made of protein fibers that
connect to epithelium.
 The only function of the basement membrane is to
attach the epithelium to the connective tissue beneath
it.
 Epithelia get oxygen and nutrients from the blood
vessels in the connective tissue beneath the basement
membrane.
Special Characteristics of
Epithelia
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Figure 4.1
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Epithelium
 Epithelium is always BIPOLAR:
 APICAL SIDE: touches the lumen (inside heart, stomach,
etc).
 BASAL SIDE: touches the basement membrane
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Classifications of Epithelia
Figure 4.2
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SIMPLE EPITHELIUM
 SIMPLE EPITHELIUM has only one cell layer.
 SIMPLE SQUAMOUS EPITHELIUM:
 SIMPLE CUBOIDAL EPITHELIUM
 SIMPLE COLUMNAR EPITHELIUM
 PSEUDOSTRATIFIED EPITHELIUM
SIMPLE SQUAMOUS (thin)
EPITHELIUM
 SIMPLE SQUAMOUS (thin) EPITHELIUM are flat cells
that allow diffusion of materials between the cells.
 This type of epithelium is in regions where a lot of
diffusion is needed from one compartment to another,
such as the lungs and a region in the kidney called the
glomerulus.
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Simple Squamous Epithelium
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Found in the lungs
Figure 4.3a
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Simple Squamous Epithelium
Found in the lungs
Found in the kidneys
(glomerulus)
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SIMPLE CUBOIDAL EPITHELIUM
 SIMPLE CUBOIDAL EPITHELIUM is cube shaped and is
also found in areas where there is a lot of material
going across from one compartment to another.
 This cell type has plenty of room for organelles.
 This epithelium is found in the intestines, and a region
of the KIDNEY called the convoluted tubules, and
places that need diffusion as well as room for cell
organelles.
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Simple Cuboidal Epithelium
Found in the kidneys
(convoluted tubules)
Figure 4.3b
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Tubule
Glomerulus
KIDNEY
Tubules are simple cuboidal
Glomerulus is simple squamous
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SIMPLE COLUMNAR EPITHELIUM
 SIMPLE COLUMNAR EPITHELIUM is shaped like a column
and are found in areas where the cells are needed for
secretion and absorption (intestines).
 When they are differentiated into GOBLET CELLS, they
produce mucus.
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Simple Columnar Epithelium
Figure 4.3c
PSEUDO-STRATIFIED COLUMNAR
EPITHELIUM
 PSEUDO-STRATIFIED COLUMNAR EPITHELIUM is a single layer
of cells that appears to be more than one layer thick, but it is
not. The nucleus on one cell is at the top, and the nucleus of
the next cell is at the bottom.
 Pseudostratified epithelium always has cilia on its apical
surface. Each cilium is a hair-like structure that moves back
and forth to move material in a certain direction.
 This type of epithelium needs goblet cells nearby to produce
the mucus that contains the material to be swept. These cells
will be found in the respiratory tract (the trachea), where the
mucous catches the debris you inhale and the cilia sweeps the
material up to your throat where you cough and swallow it.
 Its only functions are protection and mucous production.
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Pseudostratified Columnar
Epithelium
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Found in the trachea
Figure 4.3d
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A Cilium
Figure 4.8
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STRATIFIED EPITHELIUM
 STRATIFIED EPITHELIUM has more than one cell layer. The type of
epithelium is named by the APICAL layer.
 STRATIFIED SQUAMOUS EPITHELIUM:
1) Keratinized stratified squamous epithelium
2) Non-keratinized stratified squamous epithelium
 STRATIFIED CUBOIDAL EPITHELIUM
 STRATIFIED COLUMNAR EPITHELIUM
 TRANSITIONAL EPITHELIUM
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STRATIFIED SQUAMOUS EPITHELIUM
STRATIFIED SQUAMOUS EPITHELIUM: the type is
named by the apical cells. Stratified squamous
epithelium is found in regions of the body where
there is a lot of abrasions or wear-and tear, and it is
the most protective (it is the thickest).
 1) KERATINIZED STRATIFIED SQUAMOUS
EPITHELIUM has apical cells that contain a protein
called keratin, which is waterproof. All of our dry
skin is this type, and it is especially thick in the
palms and soles. It is very good at resisting
abrasions.
 2) NON-KERATINIZED STRATIFIED SQUAMOUS
EPITHELIUM does not have the keratin, so it will be
moist skin, like what is found lining the mouth and
esophagus.
Stratified Squamous Epithelium
(keratinized)
Found in dry skin
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Stratified Squamous Epithelium
(non-keratinized)
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Found in moist skin
(mouth and esophagus)
Figure 4.3e
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STRATIFIED CUBOIDAL EPITHELIUM
 STRATIFIED CUBOIDAL EPITHELIUM usually consists of
only two layers, and there is almost no diffusion
between them.
 It is found in sweat glands.
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Stratified Cuboidal Epithelium
Found in sweat glands
Figure 4.3f
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Stratified Cuboidal Epithelium
Found in Sweat Glands
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STRATIFIED COLUMNAR EPITHELIUM
 STRATIFIED COLUMNAR EPITHELIUM usually has just a
few layers and this type of epithelium inhibits diffusion
of materials.
 It is relatively rare, providing protection along
portions of the pharynx, urethra, and anus.
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Stratified Columnar Epithelium
Figure 4.3g
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TRANSITIONAL EPITHELIUM
 TRANSITIONAL EPITHELIUM can stretch and change
shape.
 This type is what lines the urinary bladder and it looks
like this as it goes from empty to full.
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Transitional Epithelium
Found in the urinary bladder
Figure 4.3h
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Connective Tissues
Types of Connective Tissues
 FIBROUS (PROPER) Connective tissues
 SPECIAL CONNECTIVE TISSUE
 Functions of Connective Tissues
 Defend the body from invasion by microorganisms
 Provide protection for delicate organs
 Establish a structural framework for the body
FIBROUS (PROPER) Connective
tissues
 FIBROUS (PROPER) Connective tissues
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ADIPOSE (fat)
RETICULAR (lymph nodes)
LOOSE (aka AREOLAR; upper dermis)
DENSE
 REGULAR (tendons and ligaments)
 IRREGULAR (lower dermis and joint capsules)
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Adipose
ADIPOSE
Main cell type is an adipocyte (stores fat)
Functions:
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Cushions organs
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Food Storage
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Insulation
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Adipose Tissue
Figure 4.12c
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Lipoma
 These are benign fat nodules in the hypodermis, usually
associated with high cholesterol levels. They are easily
surgically excised (removed)
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Liposarcoma
 Patients usually note a deep seated
mass in their soft tissue. Only when
the tumor is very large do symptoms
of pain or functional disturbances
occur.
Most frequent in middle-aged and older adults (age 40 and above),
liposarcomas are the second most common of all soft-tissue
sarcomas . Annually 2.5 cases occur per million population.
The prognosis varies depending on the site of origin, the type of
cancer cell, the tumor size, the depth, and proximity to lymph
nodes. Well-differentiated liposarcomas treated with surgery and
radiation have a low recurrence rate (about 10%) and rarely
metastasize.
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Why you got fat
 http://www.youtube.com/watch?v=mNYlIcXynwE
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 Are you more drunk than you
think?, http://fxn.ws/TqUdz9
 Women have a higher fat-to-water ratio than men do.
 A 150-pound man holds more water than a 150-pound
woman; after one drink, the woman will have a higher
concentration of booze in her blood. That leads to
greater intoxication. And her liver has to work harder to
metabolize that alcohol, prolonging her buzz.
 For every drink a woman has, it’s the equivalent of a
drink and a half for a same-sized man.
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Reticular Connective Tissue
Found in lymph node
Figure 4.12d
Reticular Connective Tissue
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Loose Connective Tissue
LOOSE (AREOLAR) connective tissue
This is the least specialized connective tissue.
The main cell type in loose and dense connective tissue is
a FIBROBLAST (a type of cell, not just a part of a
cell). Fibroblasts are what make collagen and elastic
fibers, and they also and repair wounds.
Areolar is common in areas just deep to epidermis (upper
dermis).
It does NOT have much collagen as dense because it does
not have many fibroblasts.
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Areolar Connective Tissue
Found in dermis
Figure 4.12b
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Dense Regular Connective Tissue
DENSE REGULAR connective tissue
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Dense regular and irregular connective tissue has lots of
COLLAGEN FIBERS
Dense regular has more collagen than irregular.
Dense regular fibers have a pattern, and run in same
direction
Even more strong than irregular, but only in one
direction
Ligaments and tendons are dense regular CT.
Note: tendons are not muscle tissue; they are dense
regular connective tissue.
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Dense Regular Connective Tissue
Figure 4.12f
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 NOTE: If you get injured, you’d rather break a bone
than tear a ligament, why?
 The number of fibroblasts is the same, but the ligament
has a lot more collagen to be made by each fibroblast.
 And the blood supply to bone is much better than a
ligament.
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Dense Irregular
DENSE IRREGULAR connective tissue
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Has lots of COLLAGEN FIBERS
Fibers have irregular position; no pattern
Extremely strong in all directions
Found in areas of body where strength is needed (joint
capsules and deeper layer of the dermis).
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Dense Irregular Connective Tissue
Found in joint capsules
and dermis
Figure 4.12e
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Scleroderma
 Scleroderma is a chronic systemic autoimmune disease (primarily of the
skin) characterized by fibrosis (or hardening), vascular alterations, and
autoantibodies. There are two major forms:
 Limited systemic sclerosis/scleroderma involves cutaneous manifestations
that mainly affect the hands, arms, and face. It was previously called
CREST syndrome in reference to the following complications: Calcinosis,
Raynaud's phenomenon, Esophageal dysfunction, Sclerodactyly, and
Telangiectasias. Additionally, pulmonary arterial hypertension may occur
in up to one-third of patients and is the most serious complication for this
form of scleroderma.
 Diffuse systemic sclerosis/scleroderma is rapidly progressing and affects a
large area of the skin and one or more internal organs, frequently the
kidneys, esophagus, heart, and lungs. This form of scleroderma can be
quite disabling. There are no treatments for scleroderma itself, but
individual organ system complications are treated.
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Scleroderma
Granuloma
 A granuloma is an inflammation found in many diseases.
It is a collection of immune cells known as
macrophages.
 Granulomas form when the immune system attempts to
wall off substances that it perceives as foreign but is
unable to eliminate.
 Such substances include infectious organisms such as
bacteria and fungi as well as other materials such as
keratin and suture fragments.
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Lightning
Strike
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Special Connective Tissue
Special Connective Tissue
 Cartilages
 Hyaline cartilage (most joints)
 Elastic cartilage (ear)
 Fibrocartilage (intervertebral discs)
 Bone tissues
 Compact bone (shaft of long bones)
 Spongy bone (ends of long bones)
 Blood
 Muscles (discussed more in later lectures)
 Nerves (discussed more in later lectures)
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Cartilage
Cartilages
 Main cell type is CHONDROCYTE
 Extracellular matrix is dense collagen; almost
solid, very rigid
 Avascular (no blood vessels. Torn cartilage won’t
heal).
 There are three types of cartilage:
 HYALINE CARTILAGE
 ELASTIC CARTILAGE
 FIBROCARTILAGE
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Hyaline Cartilage
Found in most joints
Figure 4.12g
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Hyaline Cartilage
Hyaline
Cartilage
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Hyaline Cartilage
Elastic Cartilage (elastin fibers)
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Found in the ear
Figure 4.12h
Elastic Cartilage
Lacunae
Elastic fibers
Chondrocytes
Found in the outer ear
Elastic cartilage
Lacunae
Chondrocytes
Elastic fibers
Outer Ear
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Fibrocartilage
Found in intervertebral
discs; resists compression
Fibrocartilage
Lacunae
Chondrocytes
Collagen fibers
Vertebral discs
Fibrocartilage
Lacunae
Chondrocytes
Collagen fibers
Vertebral discs
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Bone
Bone tissues
 Main cell type is OSTEOCYTE = “bone cell”
 Extracellular matrix is solid, full of minerals
(instead of fluid)
 Minerals are: Calcium carbonate and Calcium
phosphate (same as limestone)
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Bone Tissue: Compact Bone
Found in shaft of long bones
Figure 4.12j
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Found in ends of
long bones
Spongy
Bone
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Blood
 Blood tissue
 Main cell type is ERYTHROCYTE
 Extracellular matrix is PLASMA (no elastin or
collagen because it would form clots)
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Blood Tissue
Figure 4.12k
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Types of Membranes
Synovial
Mucous
Serous
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Synovial Membranes
 This membrane lines the inside of fluid-filled joints.
 The cellular layers are incomplete, with gaps
between adjacent cells to allow the fluid to escape
into the joint to serve as a cushion.
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Mucous Membranes
 Mucous membranes are covered in epithelium, which
are involved in absorption and secretion.
 They line cavities that are exposed to the external
environment and internal organs.
 They are located at the nostrils, the mouth, the lips,
the eyelids, the ears, the genital area, and the anus.
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Serous Membranes
 Serous membranes secrete a watery fluid.
 The fluid reduces friction from muscles or organs
rubbing against each other. Its major function is to
produce tiny amounts of watery liquid on their
opposing surfaces to reduce friction.
 The serous membrane covering the heart is the
pericardium. Inflammation here is called pericarditis.
 The serous membrane surrounding the lungs is the
pleura. Inflammation here is called pleuritis.
 The serous membrane lining the abdominal cavity is
the peritoneum. Inflammation here is called
peritonitis.
Another way to classify
epithelium
1. MOIST EPITHELIUM: there are two types:
a. MUCOSA is the cell type that produces mucous.
Therefore, pseudo-stratified columnar epithelium is a
mucous epithelium, or a mucosa.
b. SEROSA is an epithelium that has watery secretions
on the surface. This is found in sweat glands.
2. DRY EPITHELIUM is keratinized stratified squamous
epithelium.
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Collagen
COLLAGEN
 This is a type of fiber that is found in all connective
tissues (other than blood).
 It gives connective tissues an elastic consistency.
 It has very little blood supply, so it does not regenerate
well.
 It does not interfere with diffusion of materials from
one area to another; it just provides support for
connective tissues.
Collagen fibers
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Types of Glands
 Exocrine Gland
 Secretes substances into a duct (a tunnel) and then
excretes it into the lumen or onto the skin (e.g. sweat, oil)
 Endocrine Gland
 Secretes substances into the blood to be transported to
another part of the body, where it is used (e.g. hormones).
Endocrine glands are ductless. We will discuss endocrine
glands in a separate lecture.
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Exocrine Glands
 Classification of Exocrine Glands
 Type of secretion
 Method of secretion
 Structure
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Exocrine Glands
EXOCRINE GLANDS
1. Classified based on the type of secretion
a. SEROUS GLANDS secrete water, as found in sweat
glands.
b. MUCOUS GLANDS secrete mucous, as found in goblet
cells
c. MIXED GLANDS secrete mucous and water as found in
salivary glands.
d. OIL GLANDS secrete waxy and oily substances, as
found in sebaceous glands and ear wax.
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Glands
2. Classified by the method of secretion
Merocrine (Eccrine) glands
Apocrine glands
Holocrine glands
Merocrine Gland Exocytosis
2. Classified by the method of secretion
a. MEROCRINE (Eccrine) GLANDS produce
a secretion by a process called EXOCYTOSIS.
Example is sweat gland
Cell of
merocrine
gland
Vesicle
with green
secretion
inside
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The vesicle moves to
and binds with the cell
membrane, pops open
and releases the
secretion
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Merocrine Gland Functions
 Thermoregulation
 Inhibiting the growth of bacteria on the skin
 Excretion of water, electrolytes, and some drugs
 They do not function as a lubricant for the skin.
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Apocrine Glands
b. APOCRINE GLANDS accumulate material in the apical
section, the top of the cell breaks off, and the material is
released. The cells that broke down will grow again.
Examples are the mammary glands and oil glands
associated with pubic hairs. Apocrine glands are also
considered to be a type of sweat gland, but only in the
axilla and pubic regions.
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Holocrine Glands
c. HOLOCRINE GLANDS are those where the entire cell
breaks off with all the contents inside, such as
sebaceous (oil) glands. After the cell breaks off, the
other cells move in quickly and close up the gap.
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Exocrine Glands
3. Classified by their structure (what they look like)
a. UNICELLULAR GLANDS, for example a GOBLET CELL.
Goblet cells are
found in the trachea
and secrete mucous
to trap debris; then
you cough it up.
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GOBLET CELL
Glands
b. MULTICELLULAR GLANDS
Alveolar
Simple alveolar
Compound alveolar (mammary glands)
Tubular
Simple tubular (sweat glands)
Compound tubular
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Multicellular Glands
Alveolar
Tubular
Types of Multicellular Exocrine
Glands
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Figure 4.6
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Brown Recluse Spider
They like dark spaces & woodpiles.
Also cool areas in the attic
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Day 3
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Day 5
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Day 6
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Day 9
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Day 10
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Brown Recluse Spider
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Get a Venom Extractor Kit
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Get a Venom Extractor Kit
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