respiratory system - minia.edu.eg · respiratory system respiratory portion respiratory bronchioles...
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Conducting Portion
Nasal cavities
Paranasal sinuses
Nasopharynx
Trachea
Bronchi
Bronchioles
Respiratory system
Respiratory Portion Respiratory bronchioles Alveolar ducts
Alveoli
Trachea
Mucosa : epithelium, LP, elastic membrane
Submucosa: BV, lymphatic nodules, tracheal
gland
Fibrocartilagenous layer
Adventitia
Bronchiole
Bronchioles are the terminal segments of the
conductive portion. At the transition from bronchi to
bronchioles the epithelium changes to a ciliated
.absent are cartilage ,cells clara epithelium, columnar
.
ventually, in
Clara cells are dome shaped cells devoid of cilia, have secretory granules in
their apex and are known
1- To secrete glycosaminoglycans that probably protect the
bronchiolar lining.
2- It is thought that they act as progenitor cells for other types of
bronchiolar epithelial cells.
Trachea Mucosa 3
Submucosa
Fibrocartilagenous
Adventitia
intra pulmonary bronchi
Mucosa no elastic
membrane less goblet cells
muscle
cartilagenous layer plates
Adventitia
Bronchiole
Mucosa simple columnar ciliated
+ clara
Muscle
adventitia
The epithelium of the alveoli is formed by two cell types: 1.Alveolar type I cells (type I pneumocytes) are extremely flattened concern with gas exchange 2.Alveolar type II cells (type II pneumocytes) are cuboidal shaped concern with secretion of pulmonary surfactant
Alveoli
Alveolar phagocytes: Alveolar macrophages remove dust particles, degrade
pulmonary surfactant or other particles, so they are
called dust cells. Then, they move along the air
passage ways and reach the bronchioles, bronchi and
trachea where they are discharged as sputum.
.