Circulatory System


Dr. Phillips
The circulatory system supplies nourishment and oxygen to all of the body's organs and tissues through an intricate network of arteries and veins. Dr. Patel, can you tell us how the circulatory system works?

Dr. Patel
Of course, Dr. Phillips. The key organ in the circulatory system is the heart, which is divided into four chambers: the right atrium and right ventricle, and the left atrium and left ventricle.

The right ventricle sends the blood to the lungs, where carbon dioxide is removed from the blood, and oxygen is added.

The left ventricle is responsible for pumping the blood through the aorta and out to all of the body's organs and tissues.

All the major arteries initially branch out from the aorta to form the arterial portion of the circulatory system. Smaller vessels, called arterioles, branch off from the arteries. These arterioles branch off even further to become tiny vessels called capillaries.

Capillaries play an important role in the circulatory system because they're responsible for providing oxygen and nutrients to the tissues, as well as picking up the carbon dioxide and waste products. Much of this waste is then filtered out of the blood through the liver and kidneys. The blood is then returned to the heart, where it begins the entire journey again.

The heart pumps close to two thousand gallons of blood each day and, over a lifetime, beats more than two billion times without stopping.