Search results
Results from the WOW.Com Content Network
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 ...
In effect, the single arterial pCO 2 value averages out the different pCO 2 values in the different alveoli, and so makes the Bohr equation useable. The quantity of CO 2 exhaled from the healthy alveoli is diluted by the air in the conducting airways (anatomic dead space) and by gas from alveoli that are over-ventilated in relation to their ...
As the alveoli increase in size, the surfactant becomes more spread out over the surface of the liquid. This increases surface tension effectively slowing the rate of expansion of the alveoli. This also helps all alveoli in the lungs expand at the same rate, as one that expands more quickly will experience a large rise in surface tension ...
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.
An increase in Pi causes extraalveolar blood vessels to reduce in caliber, in turn causing blood flow to decrease (extraalveolar blood vessels are those blood vessels outside alveoli). Intraalveolar blood vessels (pulmonary capillaries) are thin walled vessels adjacent to alveoli which are subject to the pressure changes described by zones 1-3.
The lowest part of the lung in relation to gravity is called the dependent region. In the dependent region smaller alveolar volumes mean the alveoli are more compliant (more distensible) and so capable of more oxygen exchange. The apex, though showing a higher oxygen partial pressure, ventilates less efficiently since its compliance is lower ...
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.
For the perfusion process, the circulatory organs of the cardiovascular system such as the heart, pulmonary arteries, pulmonary veins, and alveolar capillaries are involved. The alveolar capillary specifically participates in perfusion to get in contact with the alveoli for the gas exchange and oxygen delivery to the body tissues. [1]