The Heart and blood flow

Right Atrium

Deoxygenated blood enters the right atrium through the inferior and superior vena cava.

Left Atrium

The left atrium is one of the four chambers of the heart, located on the left posterior side. Its primary roles are to act as a holding chamber for blood returning from the lungs and to act as a pump to transport blood to other areas of the heart.

Left Pulmonary Artery

The left pulmonary artery or left branch of the pulmonary artery, shorter and somewhat smaller than the right, passes horizontally in front of the descending aorta and left bronchus to the root of the left lung, where it divides into two branches.

Left Ventricle

The left ventricle is one of four chambers of the heart. It is located in the bottom left portion of the heart below the left atrium, separated by the mitral valve. As the heart contracts, blood eventually flows back into the left atrium, and then through the mitral valve, whereupon it next enters the left ventricle

Left Pulmonary Vein

The pulmonary veins are large blood vessels that receive oxygenated blood from the lungs and drain into the left atrium of the heart. There are four pulmonary veins, two from each lung. The pulmonary veins are among the few veins that carry oxygenated blood.

Right Pulmonary Artery

The right pulmonary artery or right branch of the pulmonary artery, longer and larger than the left, carries deoxygenated blood from the heart to the right lung, so that this blood can be oxygenated within the right lung. Unlike almost all other arteries, the right pulmonary artery carries deoxygenated blood

Right ventricle

The right ventricle is the chamber within the heart that is responsible for pumping oxygen-depleted blood to the lungs. The right ventricle is one of the heart's four chambers. It is located in the lower right portion of the heart below the right atrium and opposite the left ventricle.

Mitral Valve

a valve in the heart that guards the opening between the left atrium and the left ventricle, prevents the blood in the ventricle from returning to the atrium, and consists of two triangular flaps attached at their bases to the fibrous ring which surrounds the opening and connected at their margins with the ventricular walls by the chordae tendineae and papillary muscles

Tricuspid Valve

a valve that is situated at the opening of the right atrium of the heart into the right ventricle and that resembles the mitral valve in structure but consists of three triangular membranous flaps

Inferior Vena Cava

a vein that is the largest vein in the human body, is formed by the union of the two common iliac veins at the level of the fifth lumbar vertebra, and returns blood to the right atrium of the heart from bodily parts below the diaphragm

Superior Vena Cava

a vein that is the second largest vein in the human body, is formed by the union of the two brachiocephalic veins at the level of the space between the first two ribs, and returns blood to the right atrium of the heart from the upper half of the body

Interventricular Septum

the curved slanting wall that separates the right and left ventricles of the heart and is composed of a muscular lower part and a thinner more membranous upper part

Aorta

the large arterial trunk that carries blood from the heart to be distributed by branch arteries through the body

Myocardium

the middle muscular layer of the heart wall.

Right Pulmonary Veins

the vein returning oxygenated blood from the superior and middle lobes of the right lung to the left atrium; tributaries include apical anterior and posterior veins (branches) from the right superior lobe and the middle lobe vein.