Brainscape's Knowledge GenomeTM

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


See full index

FM1020 > PHYSIOLOGY - Cardiac Cycle > Flashcards

PHYSIOLOGY - Cardiac Cycle Flashcards

1
Q

What % of total ventricular volume flows into ventricles before atrial contraction?

A

Between 80-100%

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

What % of ventricular volume is pushed into ventricles by atrial contraction?

A

Up to 20%

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

What is diastesis?

A

Slow filling of ventricles - before atrial contraction

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

Under a slow heart rate, ventricular filling is complete at diastesis t/f?

A

True

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

What is tachycardia?

A

Increased heart rate

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

What happens to ventricular filling during tachycardia?

A
  • diastesis is shortened
  • contributions of atrial contraction to ventricular filling is increased
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is syncope?

A

Fainting

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

What can happen if inadequate ventricular filling occurs?

A

Fainting/syncope

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

What happens to significance of atrial contraction during intense exercise and why?

A

-atrial contraction becomes more significant
- because ventricular contraction can occur during rapid filling stage

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

In the atrial pressure curve, what does the A wave indicate?

A

The rise in pressure caused by atrial contraction

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

In the atrial pressure curve, what does the C wave indicate?

A

The increase in pressure in the atrium due to AV valves bulging into atria during ventricular systole

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

In the atrial pressure curve, what causes the V wave?

A

The rise in pressure associated with atrial filling

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

When does rapid filling of ventricles occur and what causes it?

A
  • occurs during ventricular diastole
  • Atrial pressure > Ventricular pressure since blood has been filling up the atria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

During the A wave, what does the pressure increase by in the left atrium?

A

7-8mmHg

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

During the A wave what does atrial pressure increase by in the right atrium

A

4-6mmHg

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

What causes the venous pulse?

A
  • there are no valves at the junction of the veins and atria
  • pressure changes in atria are transmitted back to large veins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a significant venous pulse in the body?

A

Jugular venous pulse

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

What are the 3 waves of the venous pulse curve and what causes them?

A

A, C, V waves
- A by atrial contraction
- C by ventricular contraction
- V by volume in atria increasing

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

What is atrial fibrillation?

A

An arrythmia which causes uncoordinated contractions of atrial fibres.

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

What is absent from the ECG in atrial fibrillation?

A

The P wave

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

What are the irregular fluctuations on the ECG during atrial fibrillation called?

A

F waves

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

What is the range of time of the interval between ventricular contractions?

A

Between 0.35 and 0.95 seconds

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

What is the normal amount of time for the interval between ventricular contractions?

A

0.8 seconds

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

Why is atrial fibrillation not life threatening, in theory?

A
  • ventricular filling is normally almost complete during diastesis.
  • normal stroke volume, despite atrial contraction not occurring
  • electrical impulse can still be propagated in ventricles through AV node, provided it is the atrial fibres that are damaged and not the SA node
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why can atrial fibrillation be dangerous?

A

Blood clots can form in the atria

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

What is the diastolic b.p of the aorta? (just before ventricles contract)

A

80mmHg

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

What is systolic b.p of aorta?

A

120mmHg

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

What causes the incisura/dicrotic notch on the aortic pressure curve?

A

There is a small amount of backflow of blood into the ventricles before the valves close (backflow needed to close valves)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How is high pressure maintained in the walls of the aorta, even in diastole?

A

The walls of the aorta are elastic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why does the pressure of the aorta decrease slowly during diastole?

A

The elastic recoil of the aorta pushes blood into peripheral arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What causes S1?

A
  • The backflow of blood against the AV valves during systole, causing them to close.
  • the turbulent blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the longest heart sound?

A

S1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the loudest heart sound?

A

S1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What stops the AV valves from flipping up into the atria?

A

Chordae tendinae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How long does S1 last?

A

0.14 seconds

36
Q

What causes S2?

A
  • upon diastole, the semilunar valves close.
  • reverberation of blood around the aortic walls
37
Q

How long does S2 last?

A

0.11 seconds

38
Q

When comparing an ECG and a phonocardiogram, when does S1 happen with respect to the ECG?

A

Just after QRS complex

39
Q

When comparing an ECG to a phonocardiogram, when does S2 happen with respect to the ECG?

A

Just after the T wave

40
Q

What is auscultation?

A

Listening to heart sounds with a stethoscope

41
Q

Is the sound of the aortic valve or pulmonic valve louder in a normal heart?

A

Aortic valve

42
Q

When someone has pulmonary hypertension, is the sound of the aortic valve or the pulmonic valve louder?

A

Pulmonic

43
Q

Where is the auscultation point for the pulmonary valve?

A

Medial end of 2nd right intercostal space

44
Q

Where is the auscultation point for the aorta?

A

Medial end of 2nd left intercostal space

45
Q

Where is the auscultation point for the tricuspid valve?

A

5th left intercostal space, just lateral to sternum

46
Q

Where is the auscultation point for the mitral valve?

A

Over apex of heart. 5th left intercostal space, midclavicular line

47
Q

How can 2 extra heart sounds be heard?

A

Using electronical amplification of the sounds

48
Q

What causes S3?

A

Blood rushing into left ventricle from atria during middle 1/3 of diastole

49
Q

Is S3 or S4 louder?

A

S3

50
Q

What kind of a sound is S3

A

A low rumbling sound

51
Q

When is S3 considered abnormal ?

A

When someone is over 40 years old

52
Q

What causes S4?

A

Inflow of blood intro ventricles following atrial contraction

53
Q

What is an aortic stenosis?

A

The hole where the aortic valve is located gets smaller

54
Q

What can aortic stenosis do to the phonocardiogram?

A

It makes S1 very loud and longer

55
Q

What can aortic regurgitation do to the phonocardiogram?

A

Causes S2 to be longer and louder.

56
Q

What point on the pressure-volume loop corresponds to pre load?

A

Point C

57
Q

What point on the left ventricle pressure-volume loop represents ESV?

A

F

58
Q

What is preload?

A

The tension on the left ventricle when it begins to contract

59
Q

What causes preload?

A

The magnitude of EDV and end diastolic pressure

60
Q

What point on the pressure-volume loop shows preload?

A

Point C

61
Q

What is afterload?

A

The force against which the muscle is acting

62
Q

What causes afterload?

A

The blood pressure in the aorta which the ventricle must exceeed to open the semilunar valves.

63
Q

What could affect the afterload?

A

Changes in b.p

64
Q

What point on the pressure-volume loop corresponds to the afterload?

A

Point D

65
Q

What is contractility?

A

The strength of contraction at a given preload and afterload

66
Q

What is another word for contractility ?

A

Ionotrophy

67
Q

What can increase contractility?

A

Drugs e.g adrenaline

68
Q

What can decrease contractility ?

A

Cardiac failure

69
Q

What is an index of contractility ?

A

Maximum dP/dt
—> maximum slope of ventricular pressure curve

70
Q

At what volume will the diastolic pressure increase rapidly and why?

A
  • At greater than 150ml
  • because the fibrous pericardium of the heart cannot fill further
71
Q

What is the Frank-Starling law?

A

The systolic pressure increases linearly with EDV

72
Q

What happens to systolic pressure at large EDVs?

A

Systolic pressure decreases because the actin and myosin filaments are stretched too far to contract properly.

73
Q

What is stroke work output?

A

The physical work done by the ventricle to eject the stroke volume

74
Q

What is volume pressure work?

A

Stroke work output

75
Q

What is external work ?

A

Stroke work output

76
Q

How can you calculate the External work value?

A

Find the area of the diastolic/systolic pressure-volume loop.

77
Q

What happens to the EW value when the heart pumps larger quantities of blood?

A

Area of the loop becomes bigger, value of EW increase.

78
Q

What happens to EW during cardiac failure?

A

EW will reduce in value.

79
Q

What is ‘re-entry’? What is it’s effect?

A
  • ‘Re-entry’ is when the cardiac muscle cells become excitable again (repolarised) i.e refractory period is shortened
  • this means that the same impulse can cause a second wave of depolarisation - leads to abnormal patterns of cardiac contraction
80
Q

What can cause re-entry?

A
  • increased tissue mass
  • decreased rate of conduction
  • shortened refractory period in response to certain drugs
81
Q

What can cause a decreased rate of conduction?

A
  • blockage of Purkinje system
  • ischaemia of the muscle
  • high blood potassium levels
82
Q

What is fibrillation?

A

Abnormal cardiac rhythms caused by re-entry which ignore the pace setting effects of the SA node.

83
Q

What is the most serious cardiac arrythmia?

A

Ventricular fibrillation

84
Q

How long does it take for ventricular fibrillation to be fatal?

A

1-3 minutes

85
Q

What does a defibrillator do?

A

Sends a high voltage alternating electrical current through the ventricles

86
Q

How does a defibrillator work?

A

Stops fibrillation by simultaneously putting all myocardial cells in a refractory state.

  • this allows autorythmic cells to regain control

FM1020 (11 decks)

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