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The main reason for exhalation is to rid the body of carbon dioxide, which is the waste product of gas exchange in humans. Air is brought into the lungs through inhalation. Diffusion in the alveoli allows for the exchange of O 2 into the pulmonary capillaries and the removal of CO 2 and other gases from the pulmonary capillaries to be exhaled ...
Almost any type of lung tumor or lung cancer can compress the alveoli and reduce gas exchange capacity. In some cases the tumor will fill the alveoli. [33] Cavitary pneumonia is a process in which the alveoli are destroyed and produce a cavity. As the alveoli are destroyed, the surface area for gas exchange to occur becomes reduced.
The alveoli are the dead end terminals of the "tree", meaning that any air that enters them has to exit via the same route. A system such as this creates dead space, a volume of air (about 150 ml in the adult human) that fills the airways after exhalation and is breathed back into the alveoli before environmental air reaches them.
The primary purpose of breathing is to refresh air in the alveoli so that gas exchange can take place in the blood. The equilibration of the partial pressures of the gases in the alveolar blood and the alveolar air occurs by diffusion. After exhaling, adult human lungs still contain 2.5–3 L of air, their functional residual capacity or FRC ...
The process of breathing does not fill the alveoli with atmospheric air during each inhalation (about 350 ml per breath), but the inhaled air is carefully diluted and thoroughly mixed with a large volume of gas (about 2.5 liters in adult humans) known as the functional residual capacity which remains in the lungs after each exhalation, and ...
The development of the respiratory system begins at about week 4 of gestation. By week 28, enough alveoli have matured that a baby born prematurely at this time can usually breathe on its own. The respiratory system, however, is not fully developed until early childhood, when a full complement of mature alveoli is present.
Elastic recoil means the rebound of the lungs after having been stretched by inhalation, [1] or rather, the ease with which the lung rebounds. With inhalation, the intrapleural pressure (the pressure within the pleural cavity) of the lungs decreases. Relaxing the diaphragm during expiration allows the lungs to recoil and regain the intrapleural ...
The alveolar type II epithelial cells are more resistant to damage, so after an insult to the alveoli, most of the damage will occur to the alveolar type I epithelial cells. [5] Left side demonstrate the structure of a normal alveolus including the difference between type I and type II alveolar epithelial cells.