heart

• The heart has four chambers:

  • Small upper chambers are called atria
  • Lower chambers are called ventricles
  • Right atrium, left atrium, right ventricle, left ventricle
• The heart has four valves that ensure blood flows in the right direction:

  • Tricuspid and pulmonary valves are on the right
  • Mitral and aortic valves are on the left
• Veins carry blood to the heart, while arteries carry blood away from the heart
• Superior and inferior vena cava are large veins that deliver deoxygenated blood into the heart:

  • Superior vena cava delivers blood from the head, neck, arms, and chest
  • Inferior vena cava delivers blood from organs in the abdomen, legs, and feet
• The pulmonary vein carries oxygenated blood from the lungs to the heart
• The aorta is the main artery that carries oxygenated blood away from the heart to the rest of the body
• Process of blood flow in the heart:

  • Deoxygenated blood from the body flows into the right atrium via the superior and inferior vena cava
  • Right atrium contracts, blood flows through the tricuspid valve into the right ventricle
  • Ventricles contract, blood flows up through the pulmonary valve into the pulmonary artery, then to the lungs
  • Oxygenated blood from the lungs enters the heart through the left atrium via the pulmonary veins
  • Left atrium contracts, blood flows through the mitral valve into the left ventricle
  • Left ventricle contracts, oxygenated blood flows up through the aortic valve into the aorta, then to the body via arteries