Ch 17-3: Cardiac Cycle & Output
Isovolumetric contraction phase
As ventricular systole begins, all four heart valves are closed during the:
5950 ml/min
Calculate cardiac output if the heart rate is 85 beats/minute, end-diastolic volume (EDV) is 130 ml, and end-systolic volume (ESV) is 60 ml.
60 ml
Calculate cardiac output if the heart rate is 85 beats/minute, end-diastolic volume (EDV) is 130 ml, and end-systolic volume (ESV) is 60 ml.
Ventricular ejection phase
During what phase does blood flow from the ventricles into the pulmonary trunk and aorta?
120 ml
End-diastolic volume (EDV) for each ventricle at the end of atrial systole is normally about:
70 ml
How much blood is pumped from each ventricle during the ventricular ejection phase?
AV valves
Increased pressure in the ventricles would close what valves?
Ventricular diastole
Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________.
The AV valves are shut while both semilunar valves are forced open
Predict the position of the valves during the ventricular ejection phase.
Isovolumetric contraction, ventricular ejection, isovolumetric relaxation
Put the phases of the cardiac cycle in the correct order, starting after ventricular filling.
The pressure in the left ventricle falls below aortic pressure
The aortic valve closes when __________.
Ventricles
The chambers that have just emptied when the second heart sound is heard are the __________.
Afterload
The force the ventricles must overcome to eject blood into their respective arteries is:
SV (stroke volume)
The volume of blood pumped by each ventricle in one heartbeat is known as:
True
True/False: Pressure in the aorta is greater than pressure in the pulmonary trunk; therefore, the left ventricle has to generate a greater pressure than the right ventricle in order to eject blood from the heart.
Greater pressure in the aorta than in the left ventricle
What causes the aortic semilunar valve to close?
The atria contract
What happens immediately after the P wave?
EDV
What largely determines preload?
SV and HR
What two values are needed in order to calculate cardiac output (CO) for a ventricle?
CO (cardiac output)
What volume should be the greatest? -CO -SV -EDV -ESV
Left ventricle
Which chamber experiences a maximum pressure of around 118 mm Hg during contraction?
Isovolumetric contraction
Ventricular systole begins during the __________ phase of the cardiac cycle.
