ANATOMY

Detailed explanation-1: -Pulmonary veins: Your pulmonary veins do the opposite job of your pulmonary arteries. They collect oxygen-rich blood and carry it from your lungs to your heart. This blood empties into your heart’s top left chamber (left atrium).

Detailed explanation-2: -Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins. Oxygen-rich blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber.

Detailed explanation-3: -Pulmonary veins are four in number and carry oxygenated blood from lungs to the left atrium of the heart [1].

Detailed explanation-4: -At the lungs, the blood picks up oxygen and drops off carbon dioxide. The blood then returns to the heart through the pulmonary veins.