The Cardiac Cycle Flashcards
What happens during late diastole?
What happens during atrial systole?
What happens during isovolumic ventricular contraction?
What happens during ventricular ejection?
What happens during isovolumic ventricular relaxation?
What is happening at A, B, C and D
A - Mitral valve closes - Inital snap back of AV valve when pressure in the ventricle rises above pressure in the atrium
B - Aortic/ pulmonary/semi-lunar valve opens
C - Aortic/ pulmonary/semi-lunar valve closes
D - Mitral valve opens becuase pressure in the atrium is greater than that of the ventricle
What is the small rise in pressure between the aortic valve closing and the mitral valve opening because of?
It is known as the dicrotic notch, small bounce in pressure due to the aortic valve closing
What is A, B and C and typical values associated?
A - Systolic pressure - 120
B - Pulse pressure - 40
C - Diastolic pressure - 80
What is the mean arterial pressure?
Roughly diastolic plus one third of the pulse pressure
What is happening at stages A,B,C,D?
A - Rapid ejection
B - Slower ejection
C - Rapid filling
D - Slower filling
What is A, B and C?
End diastolic volume
Stroke volume
End systolic volume
Where on the graph does Isovolumeric ventricular contraction and relaxation occur?
What is happening at stages A, B, C and D?
A - mitral valve opens
B - Mitral valve relaxes - pressure starts rising because the ventricle starts to relax
C - Aortic valve opens opens becuase pressure in the ventricle is greater than that of the aorta (end diastolic volume)
D - aortic valve closes – End systolic volume
What is happening in the atrium during ejection phase?
Filling with blood from the lungs (pulmonary vein)
What are average values for EDV and ESV?
EDV = 140 ml
ESV = 60 ml
Stroke volume is therefore about 80 ml