RESPIRATORY SYSTEM (II)
EXTRAPULMONARY الرئه خارجBRONCHUS
(primry BRONCHUS)
Generally have the same histological appearance as the trachea.
للتفاصيل السابق الدرس راجع اذا
INTRAPULMONARY الرئه داخلBRONCHI
(2ry & 3ry BRONCHI)
1- Mucosa.
2- Muscle coat.
3- Submucosa.
4- Adventitia.
هيستولوجيا تتكونمن
تفصل الحقا
INTRAPULMONARY BRONCHUS
INTRAPULMONARY BRONCHUS
INTRAPULMONARY BRONCHUS
(1) Mucosa: It has longitudinal طولي mucosal folds. a- Epithelium: Respiratory epith. b- L.P.: (Lamina propria) من يتكون Fibroelastic C.T. (loose C.T. rich in elastic fibers). It contains seromucous glands. “ “ lymphoid elements. N.B. No elastic lamina ( ) نو كلمه يقول الدكتور
عليها ركز يعني سؤال . معناها
INTRAPULMONARY BRONCHUS(2) Muscle coat (complete):
Two distinct مختلفتين layers of SMF ( smooth muscle fibers ) spirally حلزوني arranged in opposite direction
(crisscrossing متقاطعه bundles 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.
وعليه احمر شيء ايعليه ركز هذا خطكل في وهذا الدكتورالمحاضره
BRONCHIOLES غضاريفوال بها يوجد الاسمه انسىشيء هنا من كذا عشان بعدها بالتي
غضاريف1- Preterminal النهائيه ( 1ry ) قبل
Bronchioles (Bronchioles):
Are less than 1mm in diameter.
Each bronchiole supplies pulmonary lobule.
2- Terminal النهائيه ( 2ry ) Bronchioles.
3- Respiratory ( 3ry ) Bronchioles.
BRONCHIOLE
Preterminal Bronchioles(1) Mucosa: has longitudinal folds:
A- Epithelium:
1- Simple ciliated columnar epith نوع معرفه جدا مهمهالقادمه التراكيب في يتغير سوف النه مقارنه محل النه .االبيثيلويم
with occasional goblet cells (in larger preter. br.).
منها : مهمه -2 االخير الجزء تركيب Simple 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 جدا جدا No cartilage, No seromucous glands, No lymph .مهمهnoduLes.
TERMINAL BRONCHIOLE
Terminal Bronchioles
Similar structure to preterminal. bronchioles, but:
Epithelium:
Simple cuboidal partially ciliated epithelium
With Clara cells. من االخير الجزء تركيب مثل 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. وخصوصا جدا مهمه
بالعملي
Clara cells تقوم مرطبه خالياالقلوبليت مقام
CLARA CELLSStructure:
columnar cells (non ciliated).
Dome-shaped apices with microvilli.
Numerous apical secretory granules (of glycoproteins).
Abundant rER.
Function: مهمه1- 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.
جدا ( ) : مهمه انتشارها مواقع1 -last portion of preterminal bronchioles
2 -all terminal bronchioles3 -all respiratory portion
ALVEOLAR DUCTS
The wall of alveolar ducts consist almost ofpulmonary alveoli.
Alveolar ducts do NOT have walls of their own; They are merely فقط linear arrangement of
pulmonary alveoli. N.B. Alveolar duct → ends by: atrium → communicates with: 2-3 alveolar sacs
PULMONARY ALVEOLIDefinition:
They are small outpouchings خارجي Aب of تجيrespiratory bronchioles, alveolar ducts & alveolar sacs.
Topics: مناقشتها ستتم التي العنوانين*Interalveolar septa.
*Blood-air barrier ( Blood-gas barrier)
*Alveolar epithelium.
*Lung macrophages (alveolar macrophages).
1- INTERALVEOLAR SEPTA
Definition:
The region between 2 adjacent متجاوه alveoli.
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 كبير حجمها than type II الن
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 .or vesicular cytoplasm منتفخ Nucleus: central, rounded, vesicular.
هو الخاليا من النوع هذاالتعويض عن المسؤول
تايب خاليا يعوض 1فهو 2وتايب
Type II Pneumocytes:
- E/M: connected with type I cells by occluding junctions Dome-shaped الشكل .apical surface قبي 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).
Function:
1- Synthesis & secretion of pulmonary
surfactant وظائفه : التي 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.
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.