Cardiac cycle

• What are the three key stages of the cardiac cycle mentioned?

  Diastole, atrial systole, ventricular systole
• What does diastole mean in the context of the cardiac cycle?


  Relaxation of the heart muscles
• What does systole mean in the context of the cardiac cycle?

  Contraction of the heart muscles
• What happens to the volume of the atria during atrial systole?

  The volume decreases
• What causes the atrioventricular valves to open during atrial systole?

  Increased pressure in the atria
• What happens to the pressure in the ventricles during ventricular systole?

  The pressure increases significantly
• What is the role of the semilunar valves during ventricular systole?

  They open to allow blood to exit
• How is cardiac output calculated?

  Heart rate times stroke volume
• What is stroke volume?

  Volume of blood leaving the heart per beat
• What prevents backflow of blood in the heart?

  The valves ensure unidirectional flow
• What are the two sets of valves in the heart?

  Semilunar and atrioventricular valves
• When do the atrioventricular valves open?

  When pressure is higher in the atria
• What happens to the semilunar valves when the pressure in the arteries is higher?

  They close to prevent backflow
• How does the pressure change in the ventricles during the cardiac cycle?

  It increases during systole and decreases during diastole
• What is the significance of the thick muscular wall of the ventricles?

  It allows for a strong contraction
• What happens to the pressure in the atria during diastole?

  The pressure is very low
• What is the relationship between blood volume and pressure in the heart?

  Increased volume leads to increased pressure
• What are the stages of the cardiac cycle and their effects on the heart?

  • Diastole: Both chambers relax, volume increases, pressure decreases.
  • Atrial Systole: Atria contract, volume decreases, pressure increases.
  • Ventricular Systole: Ventricles contract, volume decreases, pressure increases significantly.
• How do the valves function during the cardiac cycle?

  • Atrioventricular valves open when atrial pressure exceeds ventricular pressure.
  • Semilunar valves open when ventricular pressure exceeds arterial pressure.
  • Valves close to prevent backflow of blood.
• What is the significance of pressure changes in the cardiac cycle?

  • Controls the opening and closing of valves.
  • Ensures unidirectional blood flow.
  • Facilitates efficient pumping of blood through the heart.
• What is the significance of the valves in the cardiac cycle?

  They ensure unidirectional blood flow
• What are the three key stages of the cardiac cycle?

  • Diastole
  • Atrial systole
  • Ventricular systole
• What does "systole" mean in the context of the heart?

  It means the heart muscles are contracting
• What happens to the volume of the atria during diastole?

  The volume increases as blood flows in
• What occurs during atrial systole?

  The atria contract, decreasing their volume
• What happens to the pressure in the atria during atrial systole?

  The pressure increases as volume decreases
• What is the result of ventricular systole?

  The ventricles contract, increasing pressure
• What causes the atrioventricular valves to close?

  Higher pressure in the ventricles than atria
• What happens to blood during ventricular systole?

  It moves from ventricles to arteries
• What is cardiac output?

  Volume of blood leaving a ventricle per minute
• How is cardiac output calculated?

  Heart rate times stroke volume
• What are the two types of valves in the heart?

  Atrioventricular and semilunar valves
• What do semilunar valves do?

  They are found between ventricles and arteries
• What causes the atrioventricular valves to open?

  Higher pressure in the atria than ventricles
• When do semilunar valves close?

  When pressure is higher in arteries than ventricles
• How do pressure changes affect valve function in the heart?

  Pressure differences open and close valves
• What happens to pressure and volume during the cardiac cycle?

  • Diastole: Both chambers relax, volume increases, pressure decreases
  • Atrial Systole: Atria contract, volume decreases, pressure increases
  • Ventricular Systole: Ventricles contract, volume decreases, pressure increases
• What is the relationship between atrial and ventricular pressure during the cardiac cycle?

  Atrial pressure must exceed ventricular pressure to open valves
• What happens to blood flow when both chambers are relaxed?

  Blood flows into the heart through the atria
• What is the significance of the thick muscular walls of the ventricles?

  They allow for strong contractions and high pressure