RESPIRATORY SYSTEM
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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.