Human Body : Arteries, veins and capillaries

There are three main types of blood vessels:

Arteries take blood away from the heart to the body organs and tissues. The artery wall is thick and muscular so it can withstand the high pressure of the blood being pumped directly from the heart

Capillaries are tiny, thin-walled vessels which form a network to take blood through the organsand tissues

Veins collect blood from the capillaries in the body and return the blood to the heart. The wall of the veins are thin, the blood is at a much lower pressure. To prevent the backflow of this lower pressure blood the veins contain valves.

You can feel a pulse in your wrist. This is the surge of blood that happens when your heart beats and pumps blood round your body.

blood is pumped from the heart to the lungs where it absorbs oxygen breathed in from the air. The blood transports that oxygen down arteries to the muscles and organs where it absorbs waste carbon dioxide.

The blood returns to the heart through the veins and is then pumped back to the lungs where it releases the carbon dioxide to be breathed out and absorbs more oxygen to continue the cycle.