Alveoli have a very large surface area, which allows for a lot of gas exchange to take place. This is because they are very thin and have a lot of folds. The total surface area of all the alveoli in the lungs is about the size of a tennis court!
The walls of the alveoli are very thin, which allows for gases to diffuse easily between the alveoli and the blood. The walls are also made up of a special type of cell called a pneumocyte, which is specialized for gas exchange.
The alveoli are lined with a moist lining. This helps to keep the alveoli moist, which is important for gas exchange. The moist lining also helps to trap dust and other particles, which prevents them from entering the bloodstream.
The alveoli are surrounded by a network of capillaries. This is where the gas exchange takes place. The oxygen in the alveoli diffuses into the blood in the capillaries, and the carbon dioxide in the blood diffuses into the alveoli.
The blood flow in the capillaries is very fast. This helps to ensure that the oxygen is quickly delivered to the rest of the body and that the carbon dioxide is quickly removed.
The alveoli are adapted for gas exchange in a number of ways. They have a large surface area, thin walls, a moist lining, a capillary network, and fast blood flow. These adaptations allow for a lot of gas exchange to take place quickly and efficiently.
