The Circulatory System
Veins, arteries and capillaries are the three types of blood vessels in the circulatory system. The blood vessels carry blood, which contains antibodies, nutrients, oxygen, electrolytes and hormones, throughout the body to be used by the organs.
Oxygen rich blood is pumped out of the left ventricle of the heart into the aorta, which is the largest artery in the body. The oxygen rich blood travels through the aorta into smaller arteries.
The capillaries sit between the arteries and the veins, connecting the two together and acting as an exchange stop. They remove oxygen and nutrients from the blood in the arteries and distribute them to the tissues in the body. They also place cellular waste, including carbon dioxide, into the veins.
Blood, with most of the oxygen removed, travels through the veins and makes a stop by the lungs to release the carbon dioxide and re-oxygenate, before heading back to the right side of the heart, where the process starts again. The entire process of the blood traveling from the heart, through the arteries, back through the veins and back to the heart, takes approximately one to two minutes.