What function do alveoli perform
Alveoli perform the function of gas exchange in the respiratory system. They are tiny, air sacs located in the lungs where oxygen from inhaled air enters the bloodstream and carbon dioxide, a waste product, is expelled from the bloodstream into exhaled air. This exchange of gases occurs through the thin walls of the alveoli, providing oxygen to the body's cells and removing carbon dioxide waste.
The alveoli are small, sac-like structures found in the lungs. They perform the following functions:
1. Gas Exchange: The alveoli are the main site for gas exchange in the respiratory system. They are surrounded by tiny blood vessels called capillaries. Oxygen from inhaled air diffuses across the alveolar walls into the capillaries, while carbon dioxide, a waste product of cellular respiration, diffuses from the capillaries into the alveoli to be exhaled.
2. Oxygenation: By facilitating the exchange of oxygen and carbon dioxide, the alveoli help oxygenate the blood. Oxygen-depleted blood from the body is transported to the lungs and redirected to alveoli, where it picks up oxygen. The oxygenated blood is then carried back to the heart, where it is pumped to the rest of the body.
3. Surface Area Expansion: The structure of the alveoli is designed to maximize the surface area available for gas exchange. The alveoli are grouped together in clusters, resembling grape clusters. This arrangement increases the total surface area available for gas exchange, allowing for efficient oxygenation of blood.
4. Humidification: The alveoli are lined with a thin layer of fluid that helps in the humidification of inhaled air. This process helps to warm and moisten the air, making it easier for the respiratory system to process.
5. Defense Mechanism: The alveoli play a role in the immune defense of the lungs. They are lined with specialized cells called alveolar macrophages, which engulf and destroy bacteria, dust particles, and other harmful substances that may be present in the inhaled air.
Overall, the alveoli are crucial for efficient gas exchange, oxygenation of the blood, and maintaining a healthy respiratory system.