The circulatory system
- The heart is a double pump – Arteries take blood away from the heart while veins take blood to the heart. The right (left as you look at the diagram, right in real life) takes deoxygenated blood to the heart, while the left takes oxygenated blood around the body.
- Arteries carry blood at high pressure
- As a rule arteries carry oxygenated blood while veins carry deoxygenated blood. However, the pulmonary vein and artery break this rule and carry the opposite type of blood.
- The arteries split off into thousands of tiny capillaries and take blood to every cell
- The veins transport the deoxygenated blood at low pressure back to the heart.
The heart is made to pump by little pulses of electricity from the wall of the right atrium
- Carry blood away from the heart (always oxygenated apart from the pulmonary artery which goes to the lungs)
- Have thick muscular walls - to withstand pressure
- Have small passageways for blood (internal lumen)
- Contain blood under high pressure
- Carry blood to the heart (always de-oxygenated apart from the pulmonary vein which goes from the lungs to the heart)
- Have thin walls