MICROANATOMY

Detailed explanation-1: -At the end of each bronchiole is a cluster of little air sacs called alveoli. Alveoli are wrapped in tiny blood vessels called capillaries. The air you breathe in fills these air sacs with oxygen-rich air. This is where the exchange of gases occurs.

Detailed explanation-2: -Oxygen moves from the alveoli to the blood through the capillaries (tiny blood vessels) lining the alveolar walls. This process is called diffusion. In the bloodstream, oxygen gets picked up by the hemoglobin in red blood cells. This oxygen-rich blood then goes to the heart, which pumps it to the body.

Detailed explanation-3: -Blood from the heart flows through these capillaries and collects oxygen from the alveoli. At the same time, carbon dioxide passes out of the capillaries and into the alveoli.

Detailed explanation-4: -The walls of the alveoli share a membrane with the capillaries. That’s how close they are. This lets oxygen and carbon dioxide diffuse, or move freely, between the respiratory system and the bloodstream. Oxygen molecules attach to red blood cells, which travel back to the heart.