How does the process of respiration work?

Respiration is the process by which living organisms convert oxygen into energy for their cells. In humans, respiration occurs through breathing, which involves the exchange of gases between the lungs and the atmosphere. The process of respiration can be divided into two parts: external respiration and internal respiration.

External respiration occurs in the lungs, where oxygen is taken in and carbon dioxide is expelled. When we inhale, air enters the lungs and moves into the alveoli, small sacs that are surrounded by capillaries. Oxygen diffuses from the air in the alveoli into the capillaries and binds to hemoglobin in the red blood cells. At the same time, carbon dioxide diffuses from the capillaries into the alveoli and is expelled when we exhale.

Internal respiration occurs at the cellular level, where oxygen is used to produce energy through a process called cellular respiration. In this process, oxygen is used to break down glucose molecules into energy that the cells can use. The waste products of this process are water and carbon dioxide, which are transported through the blood back to the lungs to be expelled.

Overall, respiration is a complex process that is essential for the survival of all living organisms.