Summary of the Blood Circulation

The circulation system in humans consists of the heart, the blood vessels and the blood. The deoxygenated blood enters the heart and is processed into oxygenated blood.

The oxygenated blood carries substances needed by the body parts to perform their activities. These substances are oxygen and food nutrients such as glucose, amino acids etc.

The oxygenated blood moves out from the heart through the blood vessels. The blood vessels are the artery, vein and capillary

The oxygenated blood moves from the heart through the aorta (artery). The artery receives the blood under high pressure. The purpose of the oxygenated blood moving out of the heart is for the blood to carry its nutrients, hormones and oxygen to the various tissues (body parts).

When the oxygenated blood gets into the artery, it moves into the veins. The veins receive the blood under low pressure.

The oxygenated blood then enters the capillaries through the veins. The capillaries are small in the form of a network that links the arteries to veins in the muscles and organs.

The capillaries are only one cell thick and this makes the food nutrients, oxygen and hormones carried by the oxygenated blood diffuse into the tissues.

The capillaries are linked to the various body tissues. Waste substances from the various tissues also enter the capillaries and are carried away.