Transcript RESPIRATORY SYSTEM

RESPIRATORY SYSTEM (II)
‫خارج الرئه‬EXTRAPULMONARY
BRONCHUS
(primry BRONCHUS)
Generally have the same histological
appearance as the trachea.
‫اذا راجع الدرس السابق للتفاصيل‬
INTRAPULMONARY ‫داخل الرئه‬
BRONCHI
(2ry & 3ry BRONCHI)
‫تتكون هيستولوجيا من‬
1234-
Mucosa.
Muscle coat.
Submucosa.
Adventitia.
‫تفصل الحقا‬
INTRAPULMONARY BRONCHUS
INTRAPULMONARY BRONCHUS
INTRAPULMONARY BRONCHUS
(1) Mucosa:
It has longitudinal ‫ طولي‬mucosal folds.
a- Epithelium: Respiratory epith.
b- L.P.: (Lamina propria) ‫يتكون من‬
Fibroelastic C.T.
(loose C.T. rich in elastic fibers).
It contains seromucous glands.
“ “
lymphoid elements.
N.B. No elastic lamina ‫الدكتور يقول كلمه ( نو ) معناها‬
‫سؤال يعني ركز عليها‬.
INTRAPULMONARY BRONCHUS
(2) Muscle coat (complete):
Two distinct ‫ مختلفتين‬layers of SMF ( smooth
muscle fibers ) spirally ‫ حلزوني‬arranged in
opposite direction
(crisscrossing ‫ متقاطعه‬bundles of spirally
arranged smooth muscle fibers “SMF”(.
(3) Submucosa:
C.T. contains:
a- Seromucous glands.
b- Lymphoid elements.
INTRAPULMONARY BRONCHUS
(4) Adventitia:
Contents: a- Loose C.T.:
Contains radially arranged elastic fibers to
connect with counterparts of neighboring
bronchial tree.
b- Irregular plates of hyaline
cartilage (complete layer).
c- Solitary lymphoid nodules.
‫اي شيء احمر وعليه خط‬
‫هذا ركز عليه الدكتور وهذا‬
‫في كل المحاضره‬
BRONCHIOLES
‫ال يوجد بها غضاريف وال بالتي‬
‫بعدها عشان كذا من هنا انسى شيء اسمه غضاريف‬
1- Preterminal ‫ ( قبل النهائيه‬1ry ) Bronchioles
(Bronchioles):
Are less than 1mm in diameter.
Each bronchiole supplies pulmonary
lobule.
2- Terminal ‫ ( النهائيه‬2ry ) Bronchioles.
3- Respiratory ( 3ry ) Bronchioles.
BRONCHIOLE
Preterminal Bronchioles
(1) Mucosa: has longitudinal folds:
A- Epithelium:
1- Simple ciliated columnar epith ‫مهمه جدا معرفه نوع‬
‫االبيثيلويم النه محل مقارنه النه سوف يتغير في التراكيب القادمه‬. with
occasional goblet cells (in larger preter. br.).
2- ‫مهمه‬: ‫ تركيب الجزء االخير منها‬Simple cuboidal mostly
ciliated with
occasional Clara cells BUT NO
goblet cells (in smaller preter. bronchioles).
B- Lamina propria: Fibroelastic C.T. (rich in elastic Fs.)
(2) Smooth muscle: 2 helically arranged SM layers.
(3) Adventitia: loose fibroelastic C.T.
N.B ‫مهمه جدا جدا‬. No cartilage, No seromucous glands, No
lymph noduLes.
TERMINAL BRONCHIOLE
Terminal Bronchioles
Similar structure to preterminal. bronchioles,
but:
Epithelium:
Simple cuboidal partially ciliated epithelium
With Clara cells. ‫مثل تركيب الجزء االخير من السابقه‬
N.B. Are less than 0.5mm in diameter.
N.B. Each supplies lung acinus.
RESP. BRONCHIOLE & ALV. DUCT
Respiratory Bronchioles
Are similar in structure to terminal bronchiolesBut:
their walls are interrupted by the
presence of few pulmonary alveoli. ‫مهمه‬
‫جدا وخصوصا‬
‫بالعملي‬
‫‪Clara cells‬خاليا مرطبه تقوم مقام‬
‫القلوبليت‬
CLARA CELLS
Structure:
columnar cells (non ciliated).
Dome-shaped apices with microvilli.
Numerous apical secretory granules (of glycoproteins).
Abundant rER.
Function: ‫مهمه‬
1- Protect the bronchiolar epith. by their glycoproteins
secretion.
2- Degrade toxins in inhaled air.
3- Divide to regenerate the bronchiolar epith.
4- Produce surfactant-like material.
: ) ‫مواقع انتشارها ( مهمه جدا‬
1- last portion of preterminal bronchioles
2- all terminal bronchioles
3- all respiratory portion
ALVEOLAR DUCTS
The wall of alveolar ducts consist almost of
pulmonary alveoli.
Alveolar ducts do NOT have walls of their own;
They are merely ‫ فقط‬linear arrangement of
pulmonary alveoli.
N.B. Alveolar duct → ends by: atrium →
communicates with: 2-3 alveolar sacs
PULMONARY ALVEOLI
Definition:
They are small outpouchings ‫ تجيّب خارجي‬of
respiratory bronchioles, alveolar ducts &
alveolar sacs.
Topics: ‫العنوانين التي ستتم مناقشتها‬
*Interalveolar septa.
*Blood-air barrier ( Blood-gas barrier)
*Alveolar epithelium.
*Lung macrophages (alveolar
macrophages).
1- INTERALVEOLAR SEPTA
Definition:
The region between 2 adjacent ‫ متجاوه‬alveoli.
Components:
(A) Alveolar Epithelium:
lines both sides of interalveolar septum.
(B) Interstitium.
INTERALVEOLAR SEPTA
& PULMONARY ALVEOLI
ALVEOLAR EPITHELIUM
(1) Type I Pneumocytes
(Type I alveolar cells)
(Squamous alveolar cells).
(2) Type II Pneumocytes
(Type II alveolar cells)
( Septal cells)
( Great alveolar cells)
ALVEOLAR EPITHELIUM
Type I Pn.
Type II Pn.
ALVEOLAR EPITHELIUM
(1) Type I Pneumocytes:
- line 95% of the alveolar surface.
- Count: less numerous ‫ الن حجمها كبير‬than type II
pneumocytes.
- L/M: simple squamous epith. ,highly attenuated cells.
- E/M: Abundant pinocytotic vesicles,
Are connected together and with type
II cells by occluding junctions.
-Function:
Exchange of gases.
Type II Pneumocyte (E/M)
Type II Pneumocytes
(2) Type II Pneumocytes:
- Line 5% of the alveolar surfaces.
- Are more numerous than type I pneumocytes.
- L/M:
Are cuboidal cells ( other textbooks: rounded
cells).
Usually found in groups of 2-3 cells.
Usually found at sites of union of septa.
Foamy ‫ رائغ‬-‫ منتفخ‬or vesicular cytoplasm.
Nucleus: central, rounded, vesicular.
‫هذا النوع من الخاليا هو‬
‫المسؤول عن التعويض فهو‬
2 ‫ وتايب‬1 ‫يعوض خاليا تايب‬
Type II Pneumocytes:
- E/M:
connected with type I cells by occluding junctions
Dome-shaped ‫ قبي الشكل‬apical surface.
Short apical microvilli.
Abundant mitochondria, RER , Well-developed
Golgi.
Membrane-bound Lamellar bodies (contain
concentric or parallel lamellae limited by a unit
membrane) (contain pulmonary surfactant).
Type II Pneumocytes:
Function:
1- Synthesis & secretion of pulmonary
surfactant ‫التي وظائفه‬:
a- It reduces effort to inflate pulm. Alveoli.
b- It has bactericidal effect.
2- Phagocytosis of pulmonary surfactant.
3-Renewal of alveolar epithelial cells:
Type II cells can divide to regenerate both
type I & type II pneumocytes.
Interstitium of interalveolar septa
(1) Continuous Pulmonary Capillaries:
-The richest capillary network in the body
- Continuous blood capillaries
- Endothelium shows numerous
pinocytotic vesicles.
(2) Interstitial C.T.:
a- C.T. Fibers: elastic fibers &
type III collagen (reticular fibers).
b- C.T. Cells: Fibroblasts, Macrophages,
Mast cells, Lymphocytes.
Blood-air barrier
BLOOD-GAS BARRIER
(BLOOD-AIR BARRIER)
Definition:
It is the region of the interalveolar septum that is
traversed by O2 & CO2
Components:
1- Thin layer of surfactant.
2- Type I pneumocyte.
3- Fused basal laminae of type I pneumocytes &
endothelial cells of the pulmonary capillary.
4- Endothelial cells of the pulmonary capillary.
Alveolar Macrophages
(Dust Cells)
Sites:
(1) In lumen of pulmonary alveoli.
(2) In pulmonary interstitium.
Function:
1- Phagocytose particulate matter (e.g. dust
& bacteria)in the lumen of pulm. alveoli &
in the interalveolar septa.
2- Phagocytose part of the surfactant.