Search results
Results from the WOW.Com Content Network
A pulmonary alveolus (pl. alveoli; from Latin alveolus 'little cavity'), also called an air sac or air space, is one of millions of hollow, distensible cup-shaped cavities in the lungs where pulmonary gas exchange takes place. [1] Oxygen is exchanged for carbon dioxide at the blood–air barrier between the alveolar air and the pulmonary ...
Iron imbalance locally in the lung thus results in higher risk of infection. Hemosiderin is the iron storage in smoker's macrophage rather than ferritin. It is formed during hemorrhage or abnormal metabolism of ferritin. [14] [15] Indeed, buildup of iron causes oxidative stress resulting in lung damage and mitochondrial dysfunction. [13]
Micrograph showing hemosiderin-laden alveolar macrophages, as seen in a pulmonary hemorrhage. H&E stain. An alveolar macrophage, pulmonary macrophage, (or dust cell) is a type of macrophage, a professional phagocyte, found in the airways and at the level of the alveoli in the lungs, but separated from their walls. [1]
The tendency for the alveoli to collapse is therefore almost the same at the end of exhalation as at the end of inhalation. Thirdly, the surface tension of the curved watery layer lining the alveoli tends to draw water from the lung tissues into the alveoli. Surfactant reduces this danger to negligible levels, and keeps the alveoli dry. [6] [37]
The major function of the lungs is gas exchange between the lungs and the blood. [67] The alveolar and pulmonary capillary gases equilibrate across the thin blood–air barrier . [ 34 ] [ 68 ] [ 69 ] This thin membrane (about 0.5 –2 μm thick) is folded into about 300 million alveoli, providing an extremely large surface area (estimates ...
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.
This is a featured picture, which means that members of the community have identified it as one of the finest images on the English Wikipedia, adding significantly to its accompanying article. If you have a different image of similar quality, be sure to upload it using the proper free license tag , add it to a relevant article, and nominate it .
The alveoli are tiny air sacs in the lungs where gas exchange takes place. The mean number of alveoli in a human lung is 480 million. [11] When the diaphragm contracts, a negative pressure is generated in the thorax and air rushes in to fill the cavity. When that happens, these sacs fill with air, making the lung expand.