The heart

• What is the primary function of the heart?

  To pump blood throughout the body
• Why does the left ventricle have thicker walls than the right ventricle?

  It needs to contract more powerfully to pump blood
• What is the role of the right ventricle?

  To pump blood to the lungs
• How do the walls of the ventricles compare to the atria?

  The ventricles have thicker walls than the atria
• What do the atrioventricular (AV) valves do?

  Link atria to ventricles and prevent backflow
• What is the function of the semi-lunar (SL) valves?

  To prevent backflow into the ventricles
• What are the cords that attach the AV valves to the ventricles called?

  Chordae tendineae
• What are the steps in a heart dissection?

  1. Lay heart with apex away.
  2. Incise right atrium.
  3. Observe thin wall of right atrium.
  4. Incise right ventricle and compare wall thickness.
  5. Observe tricuspid and pulmonary valves.
  6. Incise left atrium and ventricle, compare structures.
  7. Observe mitral and aortic valves.
  8. Identify coronary arteries and veins.
• What happens during ventricular diastole?

  The ventricles relax and fill with blood
• What occurs during atrial systole?

  The atria contract, pushing blood into ventricles
• What is the sequence of events in the cardiac cycle?

  Ventricles relax, atria contract, ventricles contract
• What is cardiac output?

  Volume of blood pumped from the left ventricle
• How is cardiac output calculated?

  Cardiac output = stroke volume x heart rate
• Calculate cardiac output with a stroke volume of 70 ml and heart rate of 75 bpm.

  $5250 \text{ ml/min}$
• Calculate stroke volume with a cardiac output of 5250 ml/min and heart rate of 75 bpm.

  $70 \text{ ml/beat}$
• Calculate heart rate with a cardiac output of 5250 ml/min and stroke volume of 70 ml/beat.

  $75 \text{ bpm}$
• What are the practice questions related to cardiac output?

  1. Calculate cardiac output with given stroke volume and heart rate.
  2. Calculate heart rate with given stroke volume and cardiac output.
  3. Calculate stroke volume with given heart rate and cardiac output.
• Which side of the heart pumps deoxygenated blood?

  The right side of the heart
• Why does the left ventricle have thicker walls than the right ventricle?

  It pumps blood to the entire body
• What are the valves that link the ventricles to the aorta and pulmonary artery?

  Semi-lunar valves
• What is the function of the semi-lunar valves?

  To prevent backflow into the ventricles
• What is the cardiac cycle?

  The sequence of events in one heartbeat
• What happens to pressure and volume in the atria during contraction?

  Pressure increases and volume decreases