MICROANATOMY

Detailed explanation-1: -ALVEOLI are the very small air sacs where the exchange of oxygen and carbon dioxide takes place. CAPILLARIES are blood vessels in the walls of the alveoli. Blood passes through the capillaries, entering through your PULMONARY ARTERY and leaving via your PULMONARY VEIN.

Detailed explanation-2: -Abstract. During respiration, it is accepted that oxygen diffuses passively from the lung alveolar spaces through the respiratory epithelium until reaching the pulmonary capillaries, where blood is oxygenated.

Detailed explanation-3: -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-4: -When you breathe in (inhale), air containing oxygen enters your windpipe, passes through the bronchi and eventually reaches the air sacs. These air sacs, called alveoli, are responsible for gas exchange. They look a bit like grapes at the end of the bronchial branches.

Detailed explanation-5: -As RBCs flow through capillaries, oxygen is continuously released from the RBC hemoglobin and eventually diffuses to the mitochondria where it is consumed.