Search results
Results from the WOW.Com Content Network
At altitude, this variation in the ventilation/perfusion ratio of alveoli from the tops of the lungs to the bottoms is eliminated, with all the alveoli perfused and ventilated in more or less the physiologically ideal manner. This is a further important contributor to the acclimatatization to high altitudes and low oxygen pressures.
Reinflation of the alveoli following exhalation is made easier by the surfactant, which reduces surface tension in the thin fluid lining of the alveoli. The fluid coating is produced by the body in order to facilitate the transfer of gases between blood and alveolar air, and the type II cells are typically found at the blood–air barrier. [19 ...
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 ...
Cellular respiration is a vital process that occurs in the cells of all [[plants and some bacteria ]]. [2] [better source needed] Respiration can be either aerobic, requiring oxygen, or anaerobic; some organisms can switch between aerobic and anaerobic respiration. [3] [better source needed]
A germination rate experiment. Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. [1]Plant physiologists study fundamental processes of plants, such as photosynthesis, respiration, plant nutrition, plant hormone functions, tropisms, nastic movements, photoperiodism, photomorphogenesis, circadian rhythms, environmental stress physiology, seed ...
SV channels have been shown to function as cation channels that are permeable to Ca 2+ ions, [35] but their exact functions are not yet known in plants. [39] Guard cells control gas exchange and ion exchange through opening and closing. K+ is one ion that flows both into and out of the cell, causing a positive charge to develop.
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.
Macrophages in the alveoli are part of the immune system which engulf and digest any inhaled harmful agents. Hair in the nostrils plays a protective role, trapping particulate matter such as dust. [14] These hairs, called vibrissae, are thicker than body hair and effectively block larger particles from entering the respiratory tract.