AP BIOLOGY

Detailed explanation-1: -Blood enters the right atrium by way of the superior vena cava and the inferior vena cava. From the right atrium, the blood flows through the tricuspid AV valve into the right ventricle. After the ventricle contracts, the blood flows through the pulmonary semilunar valve and into the pulmonary arteries.

Detailed explanation-2: -The newly oxygenated blood leaves the lungs through the pulmonary veins and heads back to the heart. It enters the heart in the left atrium, then fills the left ventricle so that it can be pumped into the systemic circulation.

Detailed explanation-3: -The right atrium and left ventricle make up part of the systemic circuit. The systemic circuit is responsible for the movement of oxygenated blood away from the heart, out to the tissues and cells, and the return of the deoxygenated back to the heart.

Detailed explanation-4: -In the systemic circulation, the left ventricle of the heart serves as the pumping chamber that circulates blood throughout the body.

Detailed explanation-5: -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.