PATHOLOGY

Detailed explanation-1: -The right ventricle (RV) pumps oxygen-poor blood through the pulmonary valve (PV) into the main pulmonary artery (MPA). From there, the blood flows through the right and left pulmonary arteries into the lungs.

Detailed explanation-2: -4. Tricuspid valve: Allows blood to pass from the right atrium to the right ventricle; prevents blood from flowing back into the right atrium as the heart pumps (systole). 5. Right ventricle: Receives blood from the right atrium; pumps blood into the pulmonary artery.

Detailed explanation-3: -The right atrium receives blood from the veins that has already circulated through the body and pumps it over to the right ventricle. The right ventricle passes the blood on to the pulmonary artery, which sends it to the lungs to pick up oxygen.