Alveola (Lat. Alveus — Poly)

), which is the main site of gas exchange between blood and air, is called the alveoli. Alveoli are located in the lungs and are small chambers that allow oxygen and carbon dioxide to pass through the thin membrane between the blood vessels and the air spaces of the lungs.

Each lung contains millions of alveoli, providing a huge surface area for gas exchange. The walls of the alveoli consist of single-layer epithelium and are surrounded by blood capillaries. The capillaries are so close to the wall of the alveoli that oxygen and carbon dioxide can easily pass between them.

Gas exchange in the alveoli occurs due to diffusion. Oxygen from the air passes through the alveolar wall into the blood capillary, where it binds to hemoglobin. At the same time, carbon dioxide, which is in the blood, passes into the alveoli and is exhaled.

The alveoli also play an important role in protecting the lungs from infections. They contain cells that can engulf and destroy bacteria and viruses. In addition, secretory cells in the alveoli produce a surfactant that helps maintain the elasticity of the lung tissue and prevents stagnation.

Lung pathologies such as emphysema, chronic bronchitis and pneumonia can lead to impaired alveolar function, which leads to impaired gas exchange and decreased oxygen levels in the blood. Therefore, the health of the alveoli and lungs in general is extremely important for maintaining the health of the body as a whole.