Search results
Results from the WOW.Com Content Network
Exhalation (or expiration) is the flow of the breath out of an organism. In animals, it is the movement of air from the lungs out of the airways , to the external environment during breathing . This happens due to elastic properties of the lungs, as well as the internal intercostal muscles which lower the rib cage and decrease thoracic volume.
This final exhalation occurs in three phases. The first phase (phase 1) has no nitrogen as that is gas that is 100% oxygen in the anatomic dead space. The nitrogen concentration then rapidly increases during the brief second phase (phase 2) and finally reaches a plateau in the third phase (phase 3).
Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a biological membrane that forms the boundary between an organism and its extracellular environment.
There are three major types of alveolar cell. Two types are pneumocytes or pneumonocytes known as type I and type II cells found in the alveolar wall, and a large phagocytic cell known as an alveolar macrophage that moves about in the lumens of the alveoli, and in the connective tissue between them.
During exhalation (breathing out), at rest, all the muscles of inhalation relax, returning the chest and abdomen to a position called the "resting position", which is determined by their anatomical elasticity. [8] At this point the lungs contain the functional residual capacity of air, which, in the adult human, has a volume of about 2.5–3.0 ...
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 ...
Next, thrust in an inward and upward motion on the diaphragm. This will force air out of the lungs and remove the blockage. Repeat these abdominal thrusts up to five times, the doctor advised.
The reverse happens during exhalation. This process (of inhalation and exhalation) is exactly the same at sea level, as on top of Mt. Everest, or in a diving chamber or decompression chamber. Fig. 14 A graph showing the relationship between total atmospheric pressure and altitude above sea level