Search results
Results from the WOW.Com Content Network
The cells in the respiratory epithelium are of five main types: a) ciliated cells, b) goblet cells, c) brush cells, d) airway basal cells, and e) small granule cells (NDES) [6] Goblet cells become increasingly fewer further down the respiratory tree until they are absent in the terminal bronchioles; club cells take over their role to some extent here. [7]
Part of the cross section is magnified to show diffusion of oxygen gas and carbon dioxide through type I cells and capillary cells. Gas exchange in the alveolus. Type I cells are the larger of the two cell types; they are thin, flat epithelial lining cells (membranous pneumocytes), that form the structure of the alveoli. [3]
The respiratory bronchioles deliver air to the exchange surfaces of the lungs. [5] They are interrupted by alveoli which are thin walled evaginations. Alveolar ducts are side branches of the respiratory bronchioles. The respiratory bronchioles are lined by ciliated cuboidal epithelium along with some non-ciliated cells called club cells. [6]
The main or primary bronchi enter the lungs at the hilum and initially branch into secondary bronchi also known as lobar bronchi that supply air to each lobe of the lung. The lobar bronchi branch into tertiary bronchi also known as segmental bronchi and these supply air to the further divisions of the lobes known as bronchopulmonary segments .
The lungs are the largest organs in the lower respiratory tract. The lungs are suspended within the pleural cavity of the thorax. The pleurae are two thin membranes, one cell layer thick, which surround the lungs. The inner (visceral pleura) covers the lungs and the outer (parietal pleura) lines the inner surface of the chest wall. This ...
The respiratory airway secretory cell (RAS), is found in the lungs of humans and some other mammals, notably ferrets. They are facultative progenitors that have important functional roles in maintaining lung airway health. Their role in maintaining the gas-exchange compartment of the lung is critical and they may be altered in chronic lung disease.
Gas exchange in the lungs occurs in millions of small air sacs; in mammals and reptiles, these are called alveoli, and in birds, they are known as atria. These microscopic air sacs have a very rich blood supply, thus bringing the air into close contact with the blood. [ 2 ]
Galen further proposed that the heat of the blood arriving in the heart produced noxious vapors that were expelled through the same pulmonary veins that first brought the pneuma. [27] He wrote that the right ventricle played a different role to the left: it transported blood to the lungs where the impurities were vented out so that clean blood ...