Process of transporting blood

• Arteries


  Bring the blood away from the heart to different tissues
• Veins


  Carry the blood back to the heart
• Capillaries


  Bring the blood from arteries and veins to the tissues
• Human heart


  • Has four chambers: two atria and two ventricles
  • Atria receive blood, ventricles pump blood to the lungs and the body
  • Has valves (atrioventricular and semilunar) that prevent backflow of blood
• Blood circulation


  1. Oxygen-poor blood from body goes to heart, then pumped to lungs for gas exchange

  2. Oxygenated blood flows back to heart, then pumped to rest of body

  3. Blood goes from right ventricle to lungs through pulmonary arteries

  4. Gas exchange occurs in lung capillaries, oxygenated blood goes to left atrium through pulmonary veins

  5. Left atrium pumps blood to left ventricle, which pumps it to body via aorta

  6. Oxygen-poor blood from upper body goes to right atrium via superior vena cava, oxygen-poor blood from lower body goes to right atrium via inferior vena cava

  7. Right atrium pumps blood to right ventricle, and the cycle repeats