alveoluksesta

Alveolus refers to a small sac-like structure found in the lungs. These microscopic air sacs are the primary sites of gas exchange in the respiratory system. Each lung contains millions of alveoli, which collectively provide a vast surface area for oxygen to diffuse into the bloodstream and for carbon dioxide to diffuse out.

The walls of the alveoli are extremely thin, composed of a single layer of flattened epithelial cells called type I pneumocytes. This thinness facilitates efficient diffusion of gases. Scattered among the type I pneumocytes are type II pneumocytes, which produce surfactant. Surfactant is a substance that reduces surface tension within the alveoli, preventing them from collapsing during exhalation and making breathing easier.

The alveoli are surrounded by a dense network of capillaries, which are tiny blood vessels. This close proximity ensures that inhaled oxygen can quickly enter the blood and be transported to the body's tissues, while carbon dioxide, a waste product, can be released from the blood into the alveoli to be exhaled. The structure and function of alveoli are crucial for maintaining cellular respiration and overall life.