PATHOLOGY

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: -Right Atrium. The right atrium is the first chamber of the heart that the blood comes into contact with as it returns from the systemic circulation, and from the blood supply to the heart.

Detailed explanation-3: -The right atrium is the first chamber that receives blood. The chamber expands as its muscles relax to fill with blood that has returned from the body. The blood enters a second, more muscular, chamber called the right ventricle. The right ventricle is one of your heart’s 2 major pumps.

Detailed explanation-4: -The right atrium receives deoxygenated blood from systemic veins; the left atrium receives oxygenated blood from the pulmonary veins.