Anatomy of the Cardiovascular System

Overview of the Heart, Arteries and Veins

From embryo until death your heart will ceaselessly beat about once every second, on average more than 2.5 billion times over the course of your life.

The heart is a powerful muscle that pumps oxygen-rich blood throughout the body, giving life to your cells. In a tireless and endless effort, the heart circulates almost 7,000 liters of blood through the body every day.

Understanding the Cardiovascular System

The cardiovascular system is composed of the heart and a complex network of arteries, veins and capillaries that act as river pipelines and tributaries traveling to every area of the body. The red blood cells are carriers of oxygen that unload their cargo, pick up carbon dioxide and toxins in the body and return to the heart to be reloaded with oxygen.

As the power supply for this system, the heart is composed of four chambers, called the atrium and ventricles, separated by valves.

Deoxygenated blood is carried by veins to the right atrium of the heart, and pumped to the lungs by the right ventricle. In the lungs the red blood cells unload carbon dioxide to be breathed out and are oxygenated and sent back to the left atrium of the heart. Next, the oxygen-rich red blood cells flow into the left ventricle. This chamber of the heart is the most muscular as the blood is pumped through the arteries and throughout the entire body.

Arteries have thick muscular walls and can push along large volumes of blood. As the arteries reach farther away from the heart, they decrease in size, like smaller streams extending from rivers. These smaller arteries are called arterioles and lead to the tiniest blood vessels, called capillaries, that surround all the organs of the body such as the stomach, the kidneys, the skin, the brain and the heart itself.

Once it reaches the organs, oxygen is delivered to each cell and carbon dioxide and toxins are picked up. The deoxygenated blood then returns to the heart traveling through small veins called venules and then through the veins back to the heart.