Brainscape's Knowledge GenomeTM

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


See full index

BME 301 > The Heart > Flashcards

The Heart Flashcards

1
Q

What is an excitable cell?

A

A cell that can generate an action potential (neuron, muscle, etc.)

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

What does an action potential lead to in muscle cells?

A

Contraction

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

What are the three kinds of muscle?

A

Smooth, skeletal, and cardiac

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

What do smooth muscle cells control?

A

Involuntary movement (digestion, etc.)

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

What do skeletal muscle cells control?

A

Voluntary movement (arm, etc.)

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

What are the top two chambers of the heart called?

A

Atria

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

What are the bottom two chambers of the heart called?

A

Ventricles

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

What is the “workhorse” of the heart?

A

Left ventricle

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

From the body, which chamber does the blood go intro first?

A

Right atrium

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

Which chamber pumps the blood to the rest of the body?

A

Left ventricle

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

What does the septum do?

A

Separate the electrical activity of the left and right ventricles

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

Why is the orientation of the myocardium important?

A

A spiral shape allows for contraction of the heart

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

Where is the tricuspid valve?

A

Between the right atrium and right ventricle

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

Where is the pulmonary valve?

A

Between the right ventricle and the pulmonary arteries

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

Where is the aortic valve?

A

Between the left ventricle and the aorta

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

Why is a heart action potential longer than a neuron action potential?

A

The function. This action potential allows for a pumping action

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

When does the peak force occur (in terms of excitation-contraction coupling)?

A

Absolute refractory period

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

How does the heart prevent tetanus?

A

The peak force occurs before relative refractory period, so the peak force must decrease before another action potential can start

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

When a muscle cell depolarizes, what direction does it occur?

A

All directions

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

Why can the SA node set the pace of the heart?

A

They are self excitatory

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

What is the heart rate set by the SA node?

A

70 bpm

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

Where do the signals propagate after the SA node?

A

Throughout the atria

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

Where is the AV node located?

A

Boundary between atria and ventricles

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

Where do the signals propagate after the AV node?

A

Into the bundle of his

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

What is the heart rate set by the AV node?

A

50 bpm

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

What is the primary pacemaker of the heart?

A

SA node

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

Where do the signals propagate after the bundle of his?

A

Left and right bundle branches

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

Why are the left and right bundle branches needed?

A

Propagate signal through ventricles faster (compared to muscle cells)

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

How does depolarization propagate in the heart?

A

From the inside (endocardium) to the outside (epicardium)

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

How does repolarization propagate in the heart?

A

From the outside (epicardium) to the inside (endocardium)

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

Why does depolarization propagate from inside to outside?

A

The inner cells are triggered first, and the wave travels outside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Why does repolarization propagate from outside to inside?

A

The action potentials near the outside are shorter than the ones near the inside

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

Where are purkinje fibers located?

A

End of the left and right bundle branches

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

What is the purpose of purkinje fibers?

A

Allow for synchronized contraction of the ventricles

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

What happens if there is failure at the bundle of his (in terms of the pace of the heart)?

A

The cells will contract at the highest frequency in that area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the major assumption of the core conductor model?

A

Homogeneous conductors and cross section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What happens when a cell is depolarized (in terms of ion flow)?

A

Positive ions (soidum) flow into the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

If an EKG signal is positive, which direction is a depolarization wave going?

A

Towards the electrode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

If an EKG signal is negative, which direction is a depolarization wave going?

A

Away from the electrode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the relationship between the voltage outside and the transmembrane voltage (core conductor model)?

A

Vo = -(ro/ro+ri)Vm ~ 0.5Vm

41
Q

What is the relationship between the current across the membrane and the transmembrane voltage (core conductor model)?

A

Km(z,t) = 1/(ro+ri) * (second derivative of voltage with respect to space)

42
Q

What happens when a cell is repolarized (in terms of ion flow)?

A

Positive ions (potassium) flow out of the cell

43
Q

If an EKG signal is positive, which direction is a repolarization wave going?

A

Away from the electrode

44
Q

If an EKG signal is negative, which direction is a repolarization wave going?

A

Towards the electrode

45
Q

Why is the repolarizing zone bigger than the depolarizing zone?

A

Repolarization is a slower process

46
Q

In a normal EKG, why do the depolarization and repolarization events have the same sign?

A

Depolarization moves towards the electrode (start inside, move outside), while repolarization moves away from the electrode (shorter time outside, longer time inside)

47
Q

What is the purpose of a gap junction?

A

Electrically link myocytes (allow for ion passage between cells)

48
Q

What is the significance of being an aggregate measure?

A

All signals are recorded and summed at a particular electrode

49
Q

What ion is responsible for the different shape in heart action potentials?

A

Calcium flows into the cell

50
Q

What chemical blocks sodium channels?

A

TTX

51
Q

If TTX was added to a heart cell, what would the resulting EKG signal look like?

A

Smaller spike at the beginning (no sodium influx)

52
Q

What does the P wave represent?

A

Atrial depolarization

53
Q

What does the PR interval represent?

A

Time from atrial depolarization to ventricular repolarization

54
Q

What does the QRS complex represent?

A

Ventricular depolarization

55
Q

What does the ST segment represent?

A

Beginning of ventricular repolarization

56
Q

What does the QT interval represent?

A

Total ventricular activity (depolarization to repolarization)

57
Q

What does the T wave represent?

A

Ventricular repolarization

58
Q

What does the U wave represent?

A

Repolarization of purkinje fibers

59
Q

What does a galvanometer do?

A

Measure current flow by utilizing magnetic fields

60
Q

What are the leads of Einthoven’s triangle?

A

RA (right arm), LA (left arm), LL (left leg)

61
Q

How can you determine a positive lead in Einthoven’s triangle?

A

An L is a positive lead

62
Q

What do we measure on a lead in Einthoven’s triangle?

A

The projection of the heart vector onto that lead

63
Q

How is a projection onto a lead calculated?

A

The dot product (magnitudes times cos(angle))

64
Q

What is the relationship between leads I, II, and III in Einthoven’s triangle?

A

I + III = II (voltages)

65
Q

Why is it better to use multiple leads?

A

Get a better idea of different events along different leads

66
Q

What modification is done to convert Einthoven’s triangle into Wilson Central Terminal?

A

Connect all the leads at a central point

67
Q

What is the advantage of the Wilson Central Terminal (compared to Einthoven’s triangle)?

A

Have a central terminal voltage as a reference node (average of three voltages)

68
Q

What modification is done to convert Einthoven’s triangle into Goldberger Augmented leads?

A

Add three leads that bisect the leads in Einthoven’s triangle

69
Q

How is the voltage of an augmented lead calculated?

A

Corner potential minus the average potential across the lead

70
Q

What is the advantage of Goldberger Augmented leads (compared to Wilson Central Terminal)?

A

Larger signal (~50%)

71
Q

Why is lead II a good indicator of heart activity?

A

Heart lies on a tilt that closely aligns with lead II

72
Q

For EKG paper, what is the scale for the x axis?

A

5 large boxes is 1 sec

73
Q

For EKG paper, what is the scale for the y axis?

A

2 large boxes is 1 mV

74
Q

What happens in acute coronary syndrome (ACS)?

A

Clot formation in the heart

75
Q

What is infarction?

A

Tissue dies due to lack of blood

76
Q

How is an infarction measured in an EKG signal?

A

Acts as a “window”, so other signals can be seen

77
Q

In an EKG signal measured near the left ventricle, there is a large negative spike at the QRS complex. What could be the underlying reason?

A

Infarction at left ventricle, thus being able to see the biological activity at the right ventricle

78
Q

In an EKG signal, the T wave is inverted. What could be the underlying reason?

A

Partial loss of tissue, returning blood flow

79
Q

In an EKG signal, the ST wave is elevated. What could be the underlying reason?

A

Myocardial infarction

80
Q

In an EKG signal, the QRS complex is normal, but the ST segment is lower than normal. What could be the underlying reason?

A

Partial occlusion in the heart

81
Q

In an EKG signal, two complexes are very close together, followed by a long pause. What could be the underlying reason?

A

Atrial ectopic heartbeat

82
Q

In an EKG signal, there is a very large negative spike, followed by a positive bump. The rest of the signal is normal. What could be the underlying reason?

A

Ventricular ectopic heartbeat

83
Q

Why does a ventricular ectopic heartbeat have a large negative spike?

A

Depolarization in wrong direction compared to normal (depolarization going from outside to inside)

84
Q

In an EKG signal, the QRS complex is normal, but the P wave is inverted. What could be the underlying reason?

A

Atrial ectopic heartbeat, close to AV node (traveling up the atria instead of down)

85
Q

In what situation could a P wave and a T wave fuse together?

A

Atrial ectopic heartbeat happening too early, fusing with the repolarization of the ventricles

86
Q

What is tachycardia?

A

Heart rate greater than 100 BPM

87
Q

In an EKG signal, the QRS complexes are all negative, and fairly rapid. What could be the underlying reason?

A

Ventricular tachycardia

88
Q

In ventricular tachycardia, what direction are the QRS complexes?

A

Negative (depolarize away from electrode)

89
Q

In an EKG signal, the signals are normal, but at a rapid rate. What could be the underlying reason?

A

Supraventricular tachycaridia

90
Q

In supraventricular tachycardia, what directions are the QRS complexes?

A

Positive (still go through AV node)

91
Q

In an EKG signal, the P waves are upright and PR intervals is normal, but the beat is rapid. What could be the underlying reason?

A

Sinus tachycardia (SA node misfiring)

92
Q

In an EKG signal, the P waves are inverted, and the PR interval is short, with the beat being rapid. What could be the underlying reason?

A

Junctional tachycardia (AV node misfiring)

93
Q

In an EKG signal, some leads are reading a positive P wave, while other leads are reading a negative P wave, with a rapid beat. What could be the underlying reason?

A

Atrial ectopic heart beat (outside SA and AV node, close to the left)

94
Q

In an EKG signal, the signal is irregularly irregular. What could be the underlying reason?

A

Atrial fibrillation

95
Q

What biological condition could underly atrial fibrillation?

A

Multiple depolarizations in the atria

96
Q

What information does a Fourier transform reveal?

A

Different frequencies in a signal

97
Q

What samples can you trust in a Fourier transform?

A

Up to half of the signaling frequency

98
Q

If we want to remove frequencies between 55 and 60 Hz, and the sampling rate is 1000 Hz, what range of frequencies would we delete in the Fourier transform?

A

55-60 Hz and 935-940 Hz

BME 301 (5 decks)

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