Human circulatory system

• The human heart works in a double circulatory system.
• The heart pumps blood around the body
• The human heart works in a double circulatory system.

  This is because the blood flows through twocircuits.

  One circuit carries oxygenated bloodaround the body.

  The other circuit carries deoxygenated blood to the lungs to pick up more oxygen
• The heart is a muscle so it needs its own blood supply.
• The coronary arteries supply the heart with its own source of oxygenated blood and glucose.