Describe the process of gas exchange in humans.

Gas exchange in humans is the process by which oxygen is taken into the body and carbon dioxide is removed, ensuring proper respiration.

This process occurs in the lungs, specifically in tiny air sacs called alveoli. When we inhale, oxygen-rich air enters the lungs and reaches the alveoli.

The walls of the alveoli are thin and surrounded by a network of capillaries. Oxygen diffuses from the alveoli into the blood in these capillaries due to a concentration gradient. At the same time, carbon dioxide diffuses from the blood into the alveoli.

The oxygenated blood is then transported to body cells, where it is used for respiration. Carbon dioxide, a waste product, is carried back to the lungs and expelled during exhalation.

Thus, gas exchange ensures a continuous supply of oxygen and removal of carbon dioxide, which is essential for maintaining life processes.