7.4 - Heart structure

• Label the heart… 


  .

  
• Why do ventricles have thicker muscular walls than atria ?

  Has to contract strongly to pump blood a large distance, either to the body or lungs
• What do the left and right atrioventricular valves prevent ?

  Back flow of blood from ventricles to atria when ventricular systole occurs
• What vessels supply the heart muscle with oxygen for respiration ?

  Coronary arteries
• How is the structure of the atria related to their function ?

  Have thin elastic walls, allow stretch and recoil
• How is the structure of ventricles related to their function ?

  Have thicker muscular walls, allow contraction to generate high pressure
• Explain why our circulatory system is closed and double ?

  Blood is contained within vessels, in a complete circuit of the body blood passes through the heart twice