1.2.6 Cardiac output, stroke volume, and heart rate

• The formula for cardiac output is Cardiac Output = Stroke Volume × Heart Rate
• What is heart rate measured in?

  Beats per minute
• Match the stroke volume factor with its description:

  Preload ↔️ Blood filling ventricles before contraction

  Afterload ↔️ Resistance the heart overcomes to pump blood

  Contractility ↔️ Strength of heart muscle contraction
• Cardiac output at rest is typically 5-6 liters per minute.


  True
• What is the definition of cardiac output?

  Blood pumped per minute
• Stroke volume is the amount of blood pumped from the heart per minute.

  False
• Stroke volume is affected by three main factors: preload, afterload, and contractility
• What is the normal resting heart rate range for adults?

  60-100 bpm
• Heart rate is measured in beats per minute, also known as bpm
• What happens to stroke volume and heart rate during exercise to increase cardiac output?

  Both increase
• What is stroke volume measured in?

  Blood pumped per beat
• Higher afterload increases stroke volume.

  False
• The normal resting heart rate for adults is generally between 60 and 100
• What is the formula for cardiac output?

  Stroke Volume × Heart Rate
• Factors affecting stroke volume in order of description

  1️⃣ Preload

  2️⃣ Afterload

  3️⃣ Contractility
• How does higher preload affect stroke volume?

  Increases stroke volume
• During exercise, cardiac output can increase to 20-25 liters/minute.


  True
• Emotional stress can increase heart rate.


  True
• What is the cardiac output range during exercise in liters per minute?

  20-25
• Order the factors affecting stroke volume from the one increasing it most to the one reducing it:

  1️⃣ Preload

  2️⃣ Contractility

  3️⃣ Afterload
• The normal resting heart rate range for adults is between 60 and 100 bpm.


  True
• Higher preload leads to greater stretch of the heart muscle, resulting in a stronger contraction
• What does increased contractility of the heart muscle lead to?

  Higher stroke volume
• Heart rate decreases during exercise.

  False
• Stroke volume is the volume of blood pumped per heart beat
• At rest, cardiac output is typically 5-6 liters/minute.


  True
• Higher preload stretches the heart muscle more, resulting in a stronger contraction
• What is the resistance the heart must overcome to pump blood out of the ventricles called?

  Afterload