MICROANATOMY

Detailed explanation-1: -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-2: -(i) The left atrium receives the oxygenated blood through the pulmonary veins. The left ventricle pumps the blood through the aorta to various parts and the de-oxygenated blood reaches right atrium.

Detailed explanation-3: -The right and left atria are the top chambers of the heart and receive blood into the heart. The right atrium receives deoxygenated blood from systemic circulation and the left atrium receives oxygenated blood from pulmonary circulation.

Detailed explanation-4: -Left atrium receives oxygenated blood from lungs while left ventricle pumps oxygenated blood to different parts of the body.