Heart Structures Functions

Epicardium (visceral pericardium)

A serous membrane that tightly hugs the external surface of the heart. It makes up part of the heart wall. Produces a serous fluid that allows the heart to beat easily in a relatively frictionless environment.

Endocardium

A thin, glistening sheet of endothelium that lines the heart chambers. It is continuous with the lining of the blood vessels leaving and entering the heart.

Inferior vena cava

Deoxygenated blood from the lower body drains into the inferior vena cava. The inferior vena cava dumps deoxygenated blood into the right atrium.

Superior vena cava

Deoxygenated blood from the upper body drains into the superior vena cava. The superior vena cava dumps deoxygenated blood into the right atrium.

Right Atrium

Deoxygenated blood leaves the body into superior and inferior vena cavas and empties into the right atrium. Deoxygenated blood leaves the right atrium and passes through the tricuspid valve into the right ventricle.

Right atrioventricular valve (tricuspid)

Deoxygenated blood leaves the right atrium and passes through the tricuspid valve into the right ventricle.

Right Ventricle

Deoxygenated blood leaves the right atrium and passes through the tricuspid valve into the right ventricle. Deoxygenated blood leaves the right ventricle through the pulmonary semilunar valve into the pulmonary artery.

Left pulmonary artery

Deoxygenated blood leaves the right ventricle through the pulmonary semilunar valve into the left pulmonary artery. Deoxygenated blood leaves the left pulmonary artery into the left lung to become oxygenated and flow back to the heart through the pulmonary vein.

Pulmonary semilunar valve

Deoxygenated blood leaves the right ventricle through the pulmonary semilunar valve into the pulmonary artery.

Pulmonary trunk

Deoxygenated blood leaves the right ventricle through the pulmonary semilunar valve into the pulmonary trunk. Deoxygenated blood from the pulmonary trunk branches into the right and left pulmonary arteries.

Right pulmonary artery

Deoxygenated blood leaves the right ventricle through the pulmonary semilunar valve into the right pulmonary artery. Deoxygenated blood leaves the right pulmonary artery into the right lung to become oxygenated and flow back to the heart through the pulmonary vein.

Interatrial septum

Divides the atria into the the left atrium (high oxygen) and the right atrium (low oxygen), preventing the mixing of low and high oxygen blood.

Interventricular septum

Divides the ventricles into the the left ventricle (high oxygen) and the right ventricle (low oxygen), preventing the mixing of low and high oxygen blood.

Left atrioventricular valve (bicuspid valve, mitral valve)

Oxygenated blood from the left atrium passes through the bicuspid valve into the left ventricle.

Left Ventricle

Oxygenated blood from the left atrium passes through the bicuspid valve into the left ventricle. Oxygenated blood from the left ventricle passes through the aortic valve into the aorta.

Ascending aorta

Oxygenated blood from the left ventricle passes through the aortic valve into ascending aorta. Oxygenated blood leaves the ascending aorta through many arteries to other areas of the body.

Aorta

Oxygenated blood from the left ventricle passes through the aortic valve into the aorta. Oxygenated blood leaves the aorta through many arteries to other areas of the body.

Aortic semilunar valve

Oxygenated blood from the left ventricle passes through the one-way aortic semilunar valve into the aorta.

Left Atrium

Oxygenated blood leaves the lungs through the pulmonary veins and empties into the left atrium. Oxygenated blood from the left atrium passes through the bicuspid valve into the left ventricle.

Myocardium

The cardiac muscle layer of the heart wall. Consists of thick bundles of cardiac muscle twisted and whorled into ringlike arrangements. It contracts.

Chordae Tendineae

Tiny white tendinous cords that anchor the bicuspid and tricuspid valve flaps to the walls of the ventricles.