ANATOMY

Detailed explanation-1: -During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs. This happens in the lungs between the alveoli and a network of tiny blood vessels called capillaries, which are located in the walls of the alveoli.

Detailed explanation-2: -Gas exchange takes place between blood and alveoli in the lungs, and then between blood and tissue cells all around the body through simple diffusion. Gasses cross the membranes at the alveolar-capillary membrane in the lungs, where oxygen enters and carbon dioxide exits the bloodstream.

Detailed explanation-3: -The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out. Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body.