Cardiac Output (Q), Stroke Volume (SV), Heart Rate (HR) Flashcards
What is the diastole phase?
When the heart relaxes and fills with blood.
What is the systole phase?
When the heart contracts and sends blood to the body and lungs.
What is venous return?
Volume of blood returning to the heart.
What is hypertrophy?
Muscle mass increasing in an organ/muscle
What is ejection fraction?
The percentage of blood pumped out from the left ventricle per beat.
What is bradycardia?
A decrease in resting heart rate below 60bpm.
Name the 4 factors that affect stroke volume
- Increased venous return = Increased stroke volume
- Cardiac hypertrophy
- Increased ejection fraction = Increased stroke volume
- Starlings Law
What is starlings law (steps)
- Increased venous return
- Greater diastolic filling
- Increased cardiac muscle stretch
- More force of contraction
- Increased ejection fraction
What is starlings law (definition)
The greater the venous return, the greater the force of contraction (ejection fraction) will be.
What happens to heart rate when stroke volume increases?
Resting HR will decrease because the heart doesnt have to beat as much in order to get the same amount of blood around the body (5Q).
Why does Bradycardia occur?
During exercise, cardiac hypertrophy occurs which results in a greater force of contraction. Therefore less beats are required to beat the same amount of blood (5Q) around the body.
Why does cardiac output remain the same during bradycardia
Because heart rate decreases, and stroke volume increases.
