The Circulatory System

The circulatory system is a complex system that is composed of the heart, arteries, veins, capillaries and blood. The function of this system is to provide nutrients and oxygen to every single corner of the human body and to dispose of waste products.



The heart’s main function is to pump blood.

The arteries are blood vessels that carry oxygenated blood away from the heart. This blood is also rich in nutrients and it is delivered to all the cells of the entire body.

The veins are blood vessels that move deoxygenated blood away from the cells and goes to the heart where it is sent to the lungs to pick up oxygen.

Capillaries are very tiny blood vessels that connect the arteries with the veins and this is where the exchange occurs. Oxygen and nutrients are delivered to the cells and carbon dioxide and other waste products are picked up from those cells.(1)

The blood is composed of red blood cells, white blood cells, and a yellow substance called plasma.

The red blood cells are the carriers of oxygen and nutrients to all the cells of the body and pick up carbon dioxide and other waste products from all those cells.

The white blood cells are the soldiers because they fight infections. They fight against viruses and bacteria.

Plasma is the liquid component of the blood. This liquid gives blood the ability to carry certain nutrients and chemicals, and provides the medium to transport red blood cells. (2)