Pneumatocytes lines the
(Alveoli) (83-M. Kaul histology 3rd) (221- LB.Singh 5th)Respiratory system - Histology* Trachea - lined by pseudostratified ciliated columnar epithelium* Intrapulmonary Bronchus - lined by pseudostratified ciliated columnar epithelium* Terminal Bronchiole - lined by simple columnar epithelium* Respiratory Bronchiole - lined by cuboidal epithelium* Atria, alveolar ducts and alveoli - lined with squamous epitheliumALVEOLI - The main support of the alveoli is provided by elastic fibres* Majority of cells lining the alveoli are the squamous cells or type 1 pneumocytes. Few are larger cells or type II pneumocytes. Type II cells secrete the surfactant which lowers surface tension and prevents alveoli from collapsing* The exchange between the blood in the capillaries and air in the alveoli takes place through(a) Cytoplasm of endothelial cell of a capillary(b) Basement membrane of the capillary(c) Basement membrane of the alveolus(d) Cytoplasm of the epithelial cells of the alveolus* In CHF, heart failure cells are present in the sputum. These cells are the alveolar macrophages, containing hemosiderin of the red blood cells from the ruptured capillaries.
Segmental bronchiole
Terminal branchioles
Respiratory bronchioles
Alveoli
Thorax