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 - Initial snap back of AV valve when pressure in ventricle rises above pressure in atrium
B - Aortic/ pulmonary/semi-lunar valve opens
C - Aortic/ pulmonary/semi-lunar valve closes
D - Mitral valve opens becuase pressure in atrium is greater than ventricle
What is the small rise in pressure between the aortic valve closing and the mitral valve opening because of?
Dicrotic notch- small bounce in pressure due to 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 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 ventricle starts to relax
C - Aortic valve opens opens because pressure in ventricle is greater than aorta (end diastolic volume)
D - aortic valve closes – End systolic volume
What is happening in the atrium during ejection phase?
Filling with blood from lungs (pulmonary vein)
What are average values for EDV and ESV?
EDV = 140 ml
ESV = 60 ml
Stroke volume is therefore about 80 ml
What is responsible for these two sounds?
What is the cause of this abnormal sound?
What is responsible for the abnormal sound seen in the phoncardiogram?
What is responsible for the abnormal sound on the phonocardiogram?
Septal defect
What are the different heard by phonocardiogram
1st = closure of AV (mitral and tricuspid) valves
2nd = closure of semi-lunar (aortic and pulmonary) valves
3rd = rapid passive filling phase
4th = active filling phase
