17.4 Mechanical Physiology of the Heart: The Cardiac Cycle Flashcards
Mechanical physiology describes the physiology of ______
Mechanical physiology describes the physiology of cardiac pumping.
What is the cardiac cycle?
The cardiac cycle is the sequence of events that takes place within the heart from one heartbeat to the next, during which each chamber has a relaxation period (diastole) and a contraction period (systole).
What are the four stages of the cardiac cycle?
There are four stages of the cardiac cycle:
- ventricular filling,
- isovolumetric contraction,
- ventricular ejection,
- isovolumetric relaxation.
What is EDV?
The volume of blood in the ventricles at the end of ventricular filling is the end-diastolic volume (EDV)
What is ESV?
the volume of ventricular blood after ventricular ejection is the end-systolic volume (ESV).
Blood is pumped out of the ventricles when the pressure in the ventricles is _______ than the pressure in the vessels into which they pump the blood.
Blood is pumped out of the ventricles when the pressure in the ventricles is higher than the pressure in the vessels into which they pump the blood.
The S1 heart sound is caused by the closing of the ______ at the beginning of __________.
The S1 heart sound is caused by the closing of the AV valves at the beginning of isovolumetric contraction.
The S2 heart sound is caused by the closing of the ________ at the beginning of ____________.
The S2 heart sound is caused by the closing of the SL valves at the beginning of isovolumetric relaxation.
Pressure changes generated by ventricular contraction and relaxation cause the blood to flow between chambers and the valves to open and close.
High pressured blood in the ventricles:
Multiple Choice:
forces both the AV valves and semilunar valves open.
forces the AV valves open.
forces the semilunar valves open.
forces both the AV valves and semilunar valves shut.
High pressured blood in the ventricles:
Multiple Choice:
forces both the AV valves and semilunar valves open.
forces the AV valves open.
forces the semilunar valves open.
forces both the AV valves and semilunar valves shut.
How much blood is pumped from each ventricle during the ventricular ejection phase?
Multiple Choice:
- 50 ml
- 70 ml
- 90 ml
- 120 ml
How much blood is pumped from each ventricle during the ventricular ejection phase?
Multiple Choice:
- 50 ml
- 70 ml
- 90 ml
- 120 ml
When is blood leaving the heart at its lowest pressure?
during diastole; when the heart chambers are at rest
