Transport systems in mammals: Structure of the heart

Pericardium

The protective sac surrounding the heart.

Atria

The two upper chambers of the heart that receive blood returning to the heart.

Ventricles

The two lower chambers of the heart that pump blood out of the heart.

Septum

The thick muscular wall that separates the left and right sides of the heart and prevents the mixing of oxygenated and deoxygenated blood.

Tricuspid valve

The valve between the right atrium and right ventricle that prevents the backflow of blood.

Bicuspid valve

The valve between the left atrium and left ventricle that prevents the backflow of blood.

Semi-lunar valves

Valves found at the openings of the pulmonary artery and aorta that prevent blood from flowing back into the ventricles.

Chordae tendineae

Tendinous cords that help prevent the heart valves from turning inside out during ventricular contraction.

Aorta

The largest artery that carries oxygenated blood from the left ventricle to the rest of the body.

Pulmonary artery

The artery that carries deoxygenated blood from the right ventricle to the lungs.

Pulmonary veins

The veins that carry oxygenated blood from the lungs to the left atrium.

Vena cava

The large veins that carry deoxygenated blood from the body into the right atrium.

Coronary arteries

Arteries that supply the walls of the heart with oxygen and nutrients.