heart structure

• Cardiac muscle


  The muscle that the heart is made of
• Cardiac muscle


  • It can contract and relax without any input from the nervous system or hormones
  • It does not fatigue as long as it has glucose and oxygen
• Coronary arteries


  The blood vessels that surround the heart and supply the cardiac muscle with oxygenated blood
• Blockages in coronary arteries

  Can cause myocardial infarction (heart attack)
• Chambers of the heart

  • Left atrium
  • Right atrium
  • Left ventricle
  • Right ventricle
• Atria


  • Have thinner muscular walls
  • Can stretch as blood moves in
  • Only need to contract to push blood into ventricles
• Ventricles


  • Have thicker muscular walls
  • Need to contract with greater force to pump blood out at higher pressure
• Right ventricle


  Pumps blood to the lungs at a lower pressure
• Left ventricle


  Pumps blood to the rest of the body at a higher pressure
• Major blood vessels


  • Aorta
  • Left pulmonary artery
  • Right pulmonary artery
  • Left pulmonary vein
  • Inferior vena cava
  • Superior vena cava
• Veins


  Bring blood into the heart
• Arteries


  Carry blood away from the heart
• Pulmonary


  Related to the lungs
• Valves


  • Semilunar valves (in arteries)
  • Atrioventricular valves (between atria and ventricles)
• Valves


  Ensure blood flows in one direction
• Septum


  Separates the left and right sides of the heart to prevent oxygenated and deoxygenated blood from mixing