THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -The lungs are made up of millions of tiny balloons called alveoli, which fill with air each time you inhale and deflate each time you exhale. The many microscopic alveoli make the lungs look like sponges. Alveoli are made up of squamous epitheliel tissue, which is very thin and elastic, like the walls of a balloon.

Detailed explanation-2: -What Are Alveoli? Bronchioles end in tiny air sacs called alveoli (say: al-VEE-uh-lie), where the exchange of oxygen and carbon dioxide actually takes place. Each person has hundreds of millions of alveoli in their lungs.

Detailed explanation-3: -Carbon dioxide (CO2) is a waste product of cellular metabolism. You get rid of it when you breathe out (exhale). This gas is transported in the opposite direction to oxygen: It passes from the bloodstream – across the lining of the air sacs – into the lungs and out into the open.