Brainscape's Knowledge GenomeTM

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


See full index

CVS Physiology > Cardiac Cycle > Flashcards

Cardiac Cycle Flashcards

1
Q

The proper function of systole is ….., the proper function of diastole is …… .

A

Ejection

Filling

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

In each cycle, the ventricles act as ………., belong to ….. pressure system in systole & ….. pressure system during diastole.

A

Compession-suction pump
High
Low

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

Atria act as …. Pumps

A

Volume

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

Cardiac cycle duration is …… at HR 75 beats, ….. of cycle is diastole & ……of cycle is systole

A

0.8 sec
2/3 (0.53 sec)
1/3 (0.27 sec)

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

In accelerated HR, ….. is increased more than …….

A

Diastole, systole

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

Atrial systole time is ……. , it is responsible for ….. of v filling, its role is increased by …..

A

0.1 sec
20-30%
Increased heart rate

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

Mention events of atrial systole.

A

Atrial pressure is increased, “a” wave in JVP
Ventricular pressure is increased
Ventricular volume in increased
Aortic pressure is dec
A-V valves are open while semilunar are closed
Heart sounds, atrial systole given 4th heart sound which is not normally audible
ECG: P wave begins before atrial systole by 0.02 sec

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

GR: Aortic pressure is decreased during atrial systole & isometric contraction phase

A

As semilunar valves are still closed with no blood ejection, while there is continuous escape of blood to the periphery.

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

Ventricular wall tension is maximally increased during ….

A

Isometric contraction phase

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

Event during isometric contraction

A

Atrial pressure is increased, “c” wave in JVP
Ventricular pressure is unchanged
Ventricular volume in increased
Aortic pressure is dec
All valves are closed
Heart sounds, S1
ECG: Q wave begins before isometric contraction by 0.02 sec

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

EDV is ….

A

~130 ml

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

GR: Occurence of 1st heart sound

A

Closure of A-V valves (valvular component) as well as ventricular muscle contraction (ventricular component).

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

Mention events that take place during rapid ejection phase

A

Atrial pressure is increased, X descent in JVP
Ventricular pressure is increased
Ventricular volume in decreased
Aortic pressure is increased
A-V valves are closed while semilunar are opened
Heart sounds, S1
ECG: ST segment & beginning of T wave

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

GR: S1 continues during rapid ejection phase

A

Due to rush of blood in aorta & pulmonary artery

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

Mention events of reduced ejection phase

A

Atrial pressure is increased, due to return of venous blood
Ventricular pressure is decreased
Ventricular volume in decreased
Aortic pressure is dec
A-V valves are closed while semilunar are opened
No Heart sounds
ECG:first half and top of T wave

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

ESV is ….

A

~50 ml

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

GR: Aortic pressure decreases during reduced ejection phase.

A

Becausecthe nlood volume escaping to the periphery is larger than the blood volume ejected by the ventricle into the aorta.

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

When does S2 occur & why?

A

Protodiastole
Blood continues to enter aorta by momentum, then suddenly the momentum is overcome, blood in aorta starts to flow back & this causes closure of aortic valve producing S2.

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

Mention events of isovolumetric relaxation

A

Atrial pressure is increased, “v” wave in JVP
Ventricular volume is unchanged (=ESV)
Ventricular pressure decreases
Aortic pressure is decreasing
All valves are closed
Heart sounds, S2
ECG: End of T wave & start of T-P segment

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

Rapid filling phase is responsible for …… of ventricular filling.

A

60-70%

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

Events of rapid filling phase

A

Atrial pressure is decreased, X descent in JVP
Ventricular volume is increased
Ventricular pressure remains very low (near zero)
Aortic pressure is decreasing
A-V valves are open while semilunar valves are closed
Heart sounds, S3
ECG: Isolectric line of T-P segment

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

GR: Reduced filling phase is called diastasis

A

Because blood passes from big veins through atria to ventricles without staying in atria.

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

Mention the longest phase of cardiac cycle , its duration & factor prolonging it.

A

Reduced filling phase, 0.2 sec, decreases heart rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Mention the most affected phase by tachycardia

Is that dangerous? Why?

A

Reduced filling phase

No, because most of the filling occurs in rapid filling phase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

GR: S3 occurence

A

Is caused by vibration set up by the rapid inflow of blood on the relaxed ventricular wall.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Mention events of reduced filling phase

A

Atrial pressure shows no change
Ventricular volume is increased
Ventricular pressure slightly increased less than 10 mmHg
Aortic pressure is decreased
A-V valves are open while semilunar valves are closed
No Heart sounds
ECG: Isolectric line of T-P segment is still recorded for 0.1 sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the effect of heart rate on filling phases?

A

When heart rate is slow, filling is more dependent on slow filling phase with little contribution of atrial systole.
When the heart accelerates the contribution of atrial systole is very important while slow filling phase is abbreviated or vanished. In cases of more severe tachycardia, even the atrial systole cannot compensate for the inadequate v filling, because of encroachment upon filling phase, leading to marked decrease in the cardiac output.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The aortic valve opens when LV pressure exceeds ….., while semilunar valve opens when RV pressure exceeds …..

A

80 mmHg

10 mmHg

29
Q

GR: Blood in the aorta doesn’t move to the periphery at the same velocity with which it is ejected

A

Because of inertia & resistance factors, this leads to stretch of the elastic aortic wall & allows storage of most kinetic energy created by contracting ventricle during period of rapid ejection.

30
Q

The inertia of blood ejected into aorta is indicated by …..

A

Time lagging of the aortic pressure tracing behind the LV pressure tracing

31
Q

GR: Blood continues to flow during reduced ejection phase

A

By momentum (total ventricular energy i.e. pressure energy + kinetic energy is still higher than the total energy in the aorta).

32
Q

GR: V pressure remains low during rapid filling phase

A

Because of synchronous relaxation of ventricukar muscle wall

33
Q

Describe the effect of atherosclerosis on BP of aorta

A

Systolic pressure goes very high in aorta & diastolic pressure goes very low i.e. arterial pressure becomes similar to ventricular pressure.

34
Q

Define stroke volume

A

It is the difference between end diastolic volume and end systolic volume.

35
Q

Describe point 1 in pressure volume loop

A

Represents end of diastole & marked by closure of MV. EDP is low & EDV is maximum.

36
Q

Describe line C to D in pressure volume loop

A

Represents the isovolumentric contraction phase. VP rises abruptly with constant volume & closed valves.

37
Q

Describe point 2 in pressure volume loop

A

LV pressure reaches above aortic distolic, leading to aortic valve opening.

38
Q

Describe line D to F in pressure volume loop

A

Represent stroke volume with rapid & reduced ejection phases, volume is decreased from EDV to ESV, it has point E whivh represents the highest level of ventricular systolic pressure, then reduced ejection with reduced pressure.

39
Q

Describe point 3 in pressure volume loop

A

Represents aortic valve closure at the end of systole, volume reaches minimum (ESV)

40
Q

Describe line F to A in pressure volume loop

A

Isovolumentric relaxation phase, both valves are closed, volume is constant but pressure falls abruptly.

41
Q

Describe point 4 in pressure volume loop

A

Mitral valve opening as the ventricular pressure becomes less than atrial pressure.

42
Q

Describe line A to C in pressure volume loop

A

It represents the 3 filling phases, volume increases from ESV to EDV, p is close to zero during rapid filling phase, inc to 5 to 8 mmHg during reduced filling phase, then to 10 mmHg during atrial systole.

43
Q

Describe significance if pressure-volume loop

A

D to F represents stroke volume
A to C represents ventricular filling
RV pressure-volume loop has same width but less in height (low p system)
Area under the curve is stroke work

44
Q

GR: Occurrence of a & c waves in JVP

A

a wave due to atrial systole & regurge of some blood into great veins
c wave due to isovolumentric contraction & bulging of tricuspid valve, also may reflect trasmitted carotic pulse in rapid ejection.

45
Q

GR: Occurrence of X & Y descents in JVP

A

X: downward displacement of AV ring by contracting ventricular muscle during rapid ejection.
Y: opening of tricuspid valve and rapid emptying of atrium into ventricles,

46
Q

GR: Occurence of v wave in JVP

A

DUE TO VENOUS return & accumulation of blood in atria while AV valves are closed

47
Q

Mention clinical indications of changes in JVP

A

No a wave in AF, huge a wave in tricuspid stenosis, huge c wave in tricuspid insufficiency, 1st degree AV block causes prolonged a-c interval, complete block results in huge a wave (Cannon wave) this occurs when atria contract against closed valve.

48
Q

Rate of trans of arterial pulse in aorta is … while in small arteries it is …..

A

4-8 m/sec

16 m/sec

49
Q

Arterial pulse waves are not dependent on blood flowing in their lumen since ….

A

It is faster than velocity of blood flow

50
Q

Pulse pressure is low in ….. & high in …..

A

Haemorrahge

Exercise

51
Q

What do the anacrotic & catacrotic limbs of arterial pulse waves represent

A

A: vibrations set up in aorta during rapid ejection phase & rise in arterial BP to max (SBP)
C: less vibrations set up in aorta during reduced ejection phase & ven diastole, coincides with dec of arterial BP to minimum (DBP)

52
Q

Define dicrotic notch & wave

A

Notch: small oscillation caused by sudden closure of aortic valve (it is larger in aorta & large arteries forming incisura)
Wave: is a reflected wave in small vessels

53
Q

Write a short note on factors affecting arterial pulse wave conduction

A

Age, dec elasticity
Distance from heart, dec elasticity
Atherosclerosis , dec elasticity

54
Q

Write a short note on factors affecting volume of arterial pulse wave

A

Very high in atheroscleosis (water hammer, collapsing, Corrigan pulse)
Decreased in aortic stenosis & hemorrhage (thready pulse)

55
Q

GR: Occurrence of heart sound in general

A

Due to vibrations set up in the blood stream caused by valve closure.

56
Q

Describe causes of S1

A
  1. Vibrations set up by closure of AV valves
  2. Muscular, due to vibrations set up papillary muscles tensing chorda tendinae
  3. Vasculohaemic due to rush of blood in aorta & pulmonary artery
57
Q

S1 is best heard oven …. & …..

A 
Apex (mitral)
Xiphisternak junction (tricuspid)
58
Q

Cause of S2

A

Vibrations set uo by closure of semilunar valves

59
Q

S2 is best heard over ….. & …..

A

Right sternocostal junction (aortic)

Left intercostal junction (pulmonary)

60
Q

S2 is splitted during …… best heard over …..

A

Inspiration

Pulmonary area

61
Q

Describe reason for S3 & conditions in which it is heard.

A

Due to vibrations set up by thinned ven wall due rush of blood at end of rapid filling phase
Children, thin persons, heart failure.

62
Q

Describe reason for S4 & conditions in which it is heard.

A

Vibrations set up by blood rushing during Atrial sysole

Mitral/tricuspid stenosis

63
Q

Compare stenosis & regurgitation

A

S: narrowing if valve leading to accelerated turbulent flow
R: blood flows backward through incompetent valve

64
Q

Causes of systolic & diastolic murmurs

A

S: mitral/tricuspid insufficiency, aortic/pulmonary stenosis
D: mitral/tricuspid stenosis, aortic/pulmonary insufficiency

65
Q

Define QS2

A

Total electromechanical systole

The time from onset QRS, till aortic valve closure indicated by S2

66
Q

Define LVET

A

Left ventricular ejection time

Period from carotid pressure rise to dicrotic notch

67
Q

Define PEP

A

Pre-ejection period

QS2-LVET

68
Q

Normal PEP/LVET is ….., increase indicates …..

A

0.35

Left venticular dyfunction with normal QS2

CVS Physiology (15 decks)

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