THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. As shown below, inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.

Detailed explanation-2: -The acinus is the structure in the lung where gas exchange occurs. The sac-like structure of the alveoli increases their surface area. In addition, the alveoli are made of thin-walled parenchymal cells. These features allow gases to easily diffuse across the cells.

Detailed explanation-3: -ALVEOLI are the very small air sacs where the exchange of oxygen and carbon dioxide takes place.

Detailed explanation-4: -The lungs of mammals are divided into millions of microscopic air sacs called alveoli (the singular is alveolus). Each alveolus is surrounded by a rich network of blood vessels for transporting gases.