circulatory system

• humans have a double circulatory system, this means that blood flows through the hearts twice in one circuit
• the coronary arteries supply blood to the heart
• Pulmonary artery & vein?

  1. deoxygenated blood is pumped out of the heart, to the lungs via the pulmonary artery
  2. oxygen diffuses into deoxygenated blood in lungs
  3. oxygenated blood flows from lungs to heart via pulmonary vein
• aorta & vena cava?

  1. oxygenated blood is pumped out of heart around body via the aorta
  2. blood in aorta is very high pressure so it can reach all tissues
  3. oxygen dissociates from blood into respiring cells, making it deoxygenated
  4. deoxygenated blood flows back to heart via vena cava
• Renal artery & vein

  1. oxygenated blood is pumped to kidneys via aorta
  2. oxygenated blood enters kidneys via renal artery
  3. oxygen diffuses out of blood into kidney cells
  4. deoxygenated blood flows out of kidneys via renal vein