THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs). The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.

Detailed explanation-2: -In a process called diffusion, oxygen moves from the alveoli to the blood through the capillaries (tiny blood vessels) lining the alveolar walls. Once in the bloodstream, oxygen gets picked up by the hemoglobin in red blood cells.

Detailed explanation-3: -The alveoli in our lungs are small sac-like structures where the exchange of gases takes place. Carbon dioxide in the blood capillary diffuses into the alveoli and is exhaled out. The oxygen in the air that enters the alveoli is taken up by the blood capillary and transported to all parts of the body.

Detailed explanation-4: -During inspiration, air containing oxygen crosses the lung alveoli through diffusion. Then, it enters the blood and travels to various organs as well as tissues. Here oxygen is exchanged for carbon dioxide. The carbon dioxide exits the capillary of the blood, enters the blood and travels back to the lungs.