The Flow of Blood around the Body
- The circulatory system consists of a closed network of blood vessels connected to the heart
- Oxygenated blood is carried away from the heart and towards organs in arteries
- These narrow to capillaries as they pass through the organ
- In the organs, respiring cells use oxygen from the blood
- The capillaries widen into veins as they move away from the organs
- Veins carry deoxygenated blood back towards the heart
- Details of the four main arteries and veins that enter and leave the heart are as follows:
Main blood vessels of the circulatory system table
Name of blood vessel | Type of vessel | Organ blood moves from | Organ blood moves to |
Aorta | Artery | Heart | Body |
Pulmonary artery | Artery | Heart | Lungs |
Vena cava | Vein | Body | Heart |
Pulmonary vein | Vein | Lungs | Heart |