Phys: The Heart As A Pump 2 Flashcards
Another name for preload
End diastolic pressure
Preload is the…
The degree of tension of the muscle when in begins to contract
Another name for afterload:
Systemic vascular resistance
What is afterload?
The load that the muscle has to contract against; heart spends more time contracting when afterload increases
Contractility
Intrinsic ability of the cardiac muscle to generate force and to shorten at a certain rate and time
Normal pressure volume loop phases:
- Isometric contraction
- Systolic ejection
- Isovolumetric relaxation
- Rapid filling
- Reduced filling
Isometric volume contraction
Period between mitral valve closing and aortic valve opening
**highest O2 consumption
Systolic ejection
Period between aortic valve opening and closing
Isovolumetric relaxation
Period between aortic valve closing and mitral valve opening
Rapid filling
Period just after mitral valve opening
Reduced filling
Period just before mitral valve closing
What does increased contractility do to the pressure volume loop?
-increase stroke volume
-increase ejection fraction
-decrease ejection systolic volume
What does increased afterload do to pressure volume loops?
-increase aortic pressure
-decrease stroke volume
-increase ejection systolic volume
What does increased preload do to pressure volume loop?
Increase stroke volume
Which side of the heart has the highest cardiac output?
They are equal
Which stage of the cardiac cycle is ventricular pressure falling and all valves are closed?
Isovolumetric relaxation
An incompetent mitral valve would allow blood to flow from the…
Left ventricle to the left atria
Sudden onset of aortic regurgitation would have what effect on the left ventricle?
Increase preload
