cardiac cycle

• What are the four major components discussed in relation to the heart?

  The four chambers, blood vessels, and valves
• What is the primary focus of the cardiac cycle?

  Pressure and volume changes in the heart
• What does "diol" refer to in the cardiac cycle?

  Relaxation of the heart muscles
• What does "sys" refer to in the cardiac cycle?

  Contraction of the heart muscles
• What happens to the Atria during "diostole"?

  They relax and fill with blood
• What occurs during "atrial systole"?

  Atria contract, increasing pressure
• What is the result of ventricular contraction?

  Increased pressure in the ventricles
• What causes the atrio-ventricular valves to open?

  Higher pressure in the Atria than ventricles
• What is the formula for calculating cardiac output?

  Heart rate times stroke volume
• What is stroke volume?

  Volume of blood leaving the heart per beat
• What happens to the semilunar valves during ventricular contraction?

  They open due to high pressure
• What do the atrio-ventricular valves prevent?

  Backflow of blood into the Atria
• What are the two types of valves mentioned?

  Semilunar and atrio-ventricular valves
• What happens when the pressure is higher in the arteries?

  Semilunar valves close
• What is the significance of pressure changes in the cardiac cycle?

  They control valve opening and closing
• What does the graph of the cardiac cycle illustrate?

  Pressure changes and valve actions
• What is the first crossover point in the graph indicative of?

  Atrial pressure exceeding ventricular pressure
• What happens to the pressure in the ventricles during relaxation?

  It decreases significantly
• What is the relationship between atrial contraction and ventricular pressure?

  Atrial contraction increases atrial pressure
• What is the significance of the thick muscular wall of the ventricles?

  It allows for strong contractions
• What does the term "unidirectional flow" refer to?

  Blood flows in one direction only
• What is the heart rate if one cardiac cycle lasts $0.28\text{ seconds}$?


  $214 \text{ beats per minute}$
• What should you consider when calculating heart rate from a graph?

  Look for repeating patterns in cycles
• What is the purpose of the TikTok mentioned in the video?

  To provide more exam questions
• What are the three key stages of the cardiac cycle?

  • Diastole (diol)
  • Atrial systole (syy)
  • Ventricular systole (syy)
• What happens to the volume and pressure during atrial systole?

  • Atria contract, decreasing volume
  • Increased pressure in the Atria
  • Blood flows into the ventricles
• What happens during ventricular systole?

  • Ventricles contract, decreasing volume
  • Increased pressure in the ventricles
  • Blood is ejected into arteries
• What occurs during diastole?

  • Both Atria and ventricles relax
  • Increased volume as blood fills chambers
  • Decreased pressure in both chambers
• How do the valves function in the cardiac cycle?

  • Open when pressure is higher behind
  • Close when pressure is higher in front
  • Prevent backflow of blood
• What is the relationship between heart rate and cardiac output?

  • Cardiac output = heart rate × stroke volume
  • Heart rate is beats per minute
  • Stroke volume is blood per beat
• What are the characteristics of the semilunar and atrio-ventricular valves?

  • Semilunar: between ventricles and arteries
  • Atrioventricular: between Atria and ventricles
  • Bicuspid has two flaps, tricuspid has three
• What is the significance of pressure changes in the cardiac cycle?

  • Control valve opening and closing
  • Ensure unidirectional blood flow
  • Indicate heart chamber activity
• What is the importance of the thick muscular wall of the ventricles?

  • Allows for strong contractions
  • Generates high pressure for blood ejection
  • Essential for effective circulation
• How can you interpret a pressure change graph of the cardiac cycle?

  • Identify when valves open and close
  • Relate pressure changes to heart activity
  • Visualize the cardiac cycle stages
• What should you do when calculating heart rate from a graph?

  • Look for repeating patterns
  • Measure duration of one cardiac cycle
  • Convert to beats per minute