Anatomy of CV System
Your heart, your arteries, veins and capillaries make up the anatomy of your cardiovascular system. A complex network, the anatomy of the cardiovascular system connects to every organ, tissue and cell of your body. Scientists studying the anatomy of the cardiovascular system have discovered that if all the blood vessels from your body were laid end to end, they would stretch for 60 000 miles, and circle the entire circumference of the earth more than twice.
The heart
Your heart muscle has four chambers; the left and right aorta above, and the left and right ventricle below. De-oxygenated blood flows into the right atrium and down into the right ventricle, where it is pumped to the lungs. Oxygenated blood flows back into the left atrium of the heart, then down into the left ventricle, before it is pumped out into the rest of the body via the aorta. The left ventricle is bigger than the right because the muscle is more powerful; it has to pump blood into the entire body at a higher pressure, whereas the right ventricle only pumps blood directly to the lungs.
Circulation
Blood circulates the body in two directions at once – to the lungs (pulmonary circulation) and to the rest of the body (systemic circulation). Your systemic circulation is a one-way system. Oxygenated blood travels away from your heart in arteries, and once it has delivered the oxygen, it travels back to your heart along a different set of blood vessels, the veins.
Blood vessels
Your body has 20 major arteries carrying oxygenated blood through your body. The arteries branch out into smaller blood vessels called arterioles, and then divide again into tiny capillaries, some only wide enough for one blood cell to travel through at a time.