By what process does gaseous exchange occur?

Gaseous exchange in the respiratory system primarily occurs through the process of diffusion. This process relies on the concentration gradient, where gases move from an area of higher concentration to one of lower concentration. In the lungs, oxygen from the alveoli (air sacs) diffuses into the blood because the concentration of oxygen is higher in the alveoli compared to the blood. Conversely, carbon dioxide diffuses from the blood into the alveoli to be expelled from the body, as the concentration of carbon dioxide is higher in the blood than in the alveoli.

Diffusion is effective for gaseous exchange due to the thin walls of the alveoli, which provide a large surface area and minimal distance for gas molecules to travel. This mechanism allows for the rapid exchange of gases essential for cellular respiration and maintaining homeostasis in the body.