ANATOMY

Detailed explanation-1: -A muscle contraction forces the blood through the tricuspid valve into the right ventricle. When the right ventricle contracts, blood is forced through the pulmonary semilunar valve into the pulmonary artery. Then it travels to the lungs. In the lungs, the blood receives oxygen then leaves through the pulmonary veins.

Detailed explanation-2: -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-3: -2. From the right atrium, blood flows through the tricuspid valve into the right ventricle. 3. The right ventricle pumps oxygen-poor blood through the pulmonary valve into the main pulmonary artery.

Detailed explanation-4: -Then the right ventricle contracts to send blood to the lungs. The tricuspid valve closes tightly so that blood does not go backward into the right atrium.