PATHOLOGY

Detailed explanation-1: -The oxygen-poor blood enters the right atrium (RA), or the right upper chamber of the heart. From there, the blood flows through the tricuspid valve (TV) into the right ventricle (RV), or the right lower chamber of the heart.

Detailed explanation-2: -The inferior and superior vena cava bring oxygen-poor blood from the body into the right atrium. The pulmonary artery carries oxygen-poor blood from the right ventricle into the lungs, where oxygen enters the bloodstream. The pulmonary veins bring oxygen-rich blood to the left atrium.

Detailed explanation-3: -Blood enters the right atrium and passes through the right ventricle. The right ventricle pumps the blood to the lungs where it becomes oxygenated. The oxygenated blood is brought back to the heart by the pulmonary veins which enter the left atrium. From the left atrium blood flows into the left ventricle.