What are Alveoli?
Alveoli are tiny, balloon-like structures located in the lungs. They are the primary site for gas exchange, allowing oxygen to enter the bloodstream and carbon dioxide to be expelled. Each lung contains millions of alveoli, significantly increasing the surface area for gas exchange.
Structure of Alveoli
- Alveoli are surrounded by a network of capillaries.
- They have thin walls, consisting of a single layer of cells, facilitating easy gas diffusion.
- The inner surface is coated with a surfactant, a substance that reduces surface tension, preventing alveoli from collapsing.
Functions of Alveoli
- Gas Exchange: Alveoli allow oxygen from inhaled air to diffuse into the blood while carbon dioxide moves from the blood into the alveoli to be exhaled.
- Surface Area: The large number of alveoli provides a vast surface area, essential for efficient gas exchange.
- Moist Environment: The moist lining of alveoli helps dissolve gases, making it easier for them to diffuse across cell membranes.
- Protection: The alveolar walls contain immune cells that help protect against pathogens and particulates.
Importance of Alveoli
- Alveoli are critical for respiration, as they ensure oxygen reaches the bloodstream, vital for cellular functions.
- Proper functioning of alveoli is essential for maintaining overall health; any damage can lead to respiratory diseases.
In summary, alveoli play a crucial role in the respiratory system, facilitating the exchange of gases necessary for sustaining life.