Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CV physio Larmon - S.Horvath > cardiac cycle > Flashcards

cardiac cycle Flashcards

1
Q

cardiac cycle is defined as

A

the cardiac events initiated by the P wave in the ecg and continuing until the next P wave.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Phase 1

A

Atrial systole, ventricular diastole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

is atrial contraction essential for ventricular filling

A

no, only accounts for about 10% of LV filling when HR is low but is important during exercise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

during phase 1 atrial systole, is the AV valve open or closed

A

open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

during phase 1 atrial systole, are the aortic and pulmonic valves open or closed?

A

closed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does the p wave represent

A

depolarization of the atria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does the a wave represent

A

atrial contraction, pressures within atrial chambers increase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

at the end of phase 1, ventricular volumes are

A

maximal. (end diastolic volume) ~120ml

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Phase 2

A

isovolumetric contraction. systole.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is special about the valves in phase 2

A

all are closed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what causes the x-descent on the atrial tracing

A

when atrial contraction is complete, atrial pressure begins to fall. this causes a slight pressure gradient reversal across the AV valves. as the pressure falls within the atria, the AV valves float upward before closure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Phase 3

A

(systole)rapid ejection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

phase 3 aortic and pulmonic valves are

A

open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

phase 3 AV valves are

A

closed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why does ejection occur?

A

total energy of the blood in the ventricles exceeds the total energy of the blood in the aorta and PA. an aery gradient is present.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

maximal outflow velocity is reached

A

early in the ejection phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what heart sounds are typically heart during ejection?

A

none. the opening of healthy heart valves is silent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

x’ descent

A

occurs as the base of the atria are pulled downward, expanding the atrial chambers (decreasing initial atrial pressure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what do atria do in phase 3

A

fill with blood from respective venous inflow tracts. volume is increasing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

phase 4

A

(systole) reduced ejection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

during phase 4, aortic and pulmonic valves are

A

open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

during phase 4, AV valves are

A

closed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what does the T wave represent

A

ventricular repolarization

24
Q

phase 5

A

isovolumic relaxation. (diastole)

25
Q

phase 5 valves are?

A

all closed

26
Q

what causes the second heart sound

A

closure of aortic and pulmonic valves (a before p)

27
Q

incisura (dicrotic notch) represents

A

aortic / pulmonic valve closure

28
Q

pressure rapidly falls in the ventricle, but aortic and PA pressure..

A

is not abrupt bc of potential energy in their elastic walls and because systemic and pulmonic vascular resistances impede the flow of blood into distributing arteries of the systemic and pulmonary circulations.

29
Q

why do ventricular volumes remain constant in phase 5?

A

because all valves are closed

30
Q

End-Systolic volume (ESV)

A

the residual volume of blood that remains in the ventricle.

31
Q

what is the ESV in the LV?

A

50ml

32
Q

stroke volume

A

the difference between end diastolic volume and end systolic volume.

33
Q

what is the approx stroke volume in the ventricle

A

70ml

34
Q

phase 6

A

rapid ventricular filling. diastole

35
Q

which valves are open in phase 6

A

AV valves

36
Q

which valves are closed in phase 6

A

aortic and pulmonic

37
Q

what contributes to rapid, passive filling of the ventricles?

A

the ventricles are still relaxing, causing pressures to still fall within them. atrial volumes are maximal just prior to AV valve opening.

38
Q

what does the v-wave represent

A

peak of the atrial pressure just before the AV valve opens

39
Q

what is y descent

A

opening of the AV valve that causes a rapid fall in atrial pressure

40
Q

what sounds do AV valves make as they open

A

none

41
Q

s3

A

may occur during rapid filling. tensing of the chord tendinae and AV ring. pathological in adults and often associated with ventricular dilation.

42
Q

phase 7

A

reduced ventricular filling (diastole)

43
Q

phase 7 which valves are open

A

AV valves

44
Q

phase 7 which valves are closed

A

aortic and pulmonic

45
Q

during what phase is ventricular filling nearing completion

A

7

46
Q

as the ventricles fill with blood they become

A

less compliant (stiff) and pressures rise

47
Q

without compensatory mechanisms, the cycle length reduction in higher heart rates would cause

A

less ventricular filling

48
Q

what phases are part of ventricular systole

A

2 3 4

49
Q

what phases are part of ventricular diastole

A

1 5 6 7

50
Q

what causes heart sounds

A

closing of valves

51
Q

what causes the first heart sound

A

closure of AV valves

52
Q

during which phase is the majority of blood ejected from the LV

A

phase 3 rapid ejection

53
Q

during which phase does most of the filling of the LV occur

A

6 rapid ventricular filling

54
Q

how much does atrial kick usually contribute to ventricular filling

A

10%

55
Q

if a person is tachycardia,how much does atrial kick contribute

A

up to 40%of ventricular filling

56
Q

during A-fib, what happens to the contribution of atrial contraction to ventricular filling

A

it is lost, leading to inadequate filling.

CV physio Larmon - S.Horvath (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions