Section 2 Lecture 4 Flashcards
Change in pressure from pulmonary artery to the left atrium:
15 mmHg
Change in pressure from aorta to the right atrium:
90 mmHg
ventricular filling happens during which phase of the cardiac cycle?
diastolic phase
What valves are open and which closed during ventricular filling (diastolic phase)?
The AV valves are open and the semilunar valves are closed
How much does each ventricle take in with each filling cycle?
140 ml (cc)
T or F? The ventricle fills in a linear fashion during diastole.
F.
What valves are open and which closed during ventricular ejection (systolic phase)?
The AV’s valves must be closed and semilunar open
Avg SV:
70 cc
Ejection fraction for the avg person:
0.5 (70/140)
How much blood is typically left in the ventricle after contraction?
70 cc
Is there a larger change in pressure during unstressed volumetric change or stressed volumetric change?
stressed (passive tension)
What is the first sound heard, the “lub?”
mitral valve closing
What is the second sound heard, the “dub?”
aortic valve closing (semilunar)
The A-V valve is bw:
the right atrium and right ventricle
SV =
EDV - ESV
Ejection Fraction =
SV/ EDV
initiate IV contraction occurs at this point in the ECG:
R
normal systole in an ECG:
Bw beg of R and end of T
diastole in an ECG:
T to R (including P) wave
the Ap that ignites system is found at this point of the ECG:
P wave
Returning to resting state in an ECG:
T wave
The only time that the ventricular P is higher than the aortic?
ejection
When is atrial P lower than ventricular?
isovolumetric contraction, ejection, and isovolumetric relaxation
When is atrial P higher than aortic P?
never
The mitral valve closes at the:
end of atrial systole/ beginning of isovoumetric contraction
The aortic valve opens at the:
end of isovoumetric contraction/ beginning of ejection
The aortic valve closes at the:
end of ejection / beginning of isovolumetric relaxation
The mitral valve closes at the:
end of isovolumetric relaxation/ beginning of rapid inflow
When is aortic pressure higher than ventricular?
always except for during ejection
When do the bicuspid and tricuspid valves close, in terms of pressure gradients?
when the atrial pressure falls below aortic pressure
Isovolumetric contraction occurs between these 2 points of the ECG:
R and S
Atrial systole occurs bw these 2 points on the ECG:
bw P and R
Ejection occurs bw these 2 points on the ECG:
S to after the T wave
How much extra volume is pushed into the ventricle with each cycle, what percent of the normal filling stroke?
5-10%
What is the beginning of systole initiated by:
R wave
Stroke volume is measured bw what two points on the ECG?
S to after the T wave
