The aorta is the main and largest artery in the human body. It originates from the left ventricle.

The aortic valve lies at the base of the aorta. It permits blood blood to leave the left ventricle as it contracts.

The inferior vena cava and superior vena cava carry blood to the right atrium.

The left atrium and right atrium receive blood returning to the heart from the circulatory system. These upper chambers of the heart have thin walls.

The left ventricle and right ventricle receive blood from the atria and contract to pump blood into the arteries.

The mitral valve or bicuspid valve has two cusps (flaps). It lies between the left atrium and the left ventricle.

The myocardium is the thick middle layer of the heart wall. It consists of cardiac muscle tissue.

The pericardium is a double-layered sac containing the heart and the roots of the large blood vessels to which it attaches.

The pulmonary trunk starts at the right ventricle and divides to form the pulmonary arteries. It carries blood to the lungs.

The pulmonary valve lies at the base of the pulmonary trunk. It allows blood to leave the right ventricle and prevents backflow.

The pulmonary veins transfer oxygenated blood from the lungs to the heart.

The wall-like septum separates the left and right atria and ventricles.

The tricuspid valve has tree cusps (flaps). It allows blood to move from the right atrium into the right ventricle and closes during contraction of the ventricle to prevent backflow.