What is Alveoli ????
Analveolusis a balloon-like structure that has the form of a hollow cavity.Found in thelungs,the pulmonary alveoli are the terminal ends of therespiratory treefrom either alveolar sacs oralveolar ducts, which are both sites of gas exchange with thebloodas well.Alveoli are particular to mammalian lungs.The alveolar membrane is the gas-exchange surface. Carbon dioxide rich blood is pumped from the rest of the body into thealveolar blood vesselswhere, throughdiffusion, it releases its carbon dioxide and absorbs oxygen.
Alveoli are small air sacs in the lungs, as small as a grain ofsand. There are billions of these in the lungs, and the purposeof these alveoli are to supply de-oxygenated blood with a supplyof oxygen through gas exchange. They are well-equipped to dothis, as well. The first reason is because the cappillaries thatthe alveoli are supplying with oxygen are spread all over theoutside of them, meaning there is more surface area to performgaseous exchange on. The second reason is because the alveoliwalls are only one cell thick, meaning the oxygen only has twocells to go through, the alveoli wall, and the capillary wall.