Brainscape's Knowledge GenomeTM

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


See full index

A&P 1 > Exam 4 - Lecture 3 > Flashcards

Exam 4 - Lecture 3 Flashcards

1
Q

Anything that sends electrons towards a positive electrode will

A

Give a positive reading/positive deflection

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

If we have depolarization in one direction causing a negative deflection, repolarization in the same direction would cause

A

Positive deflection

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

If we have depolarization in one direction causing a negative deflection, repolarization in the same direction would cause

A

Positive deflection

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

Phase 4 of ventricle muscle is very ____

A

Slightly sloped.

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

Phase 4 of SA node is also called

A

Diastolic depolarization or phase 4 depolarization

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

Phase 0 of SA node

A

Upward stroke up action potential, not as sloped as most AP.

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

In the nodal areas, phase 0 is ______ channels.

A

Slow L-type Ca++ channels.

Slower to open, slower to close.

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

Duration/slope of phase 0 is very important because

A

Determines how fast the action potentials travel throughout the heart.

If it’s super fast, everything else is super fast from sodium traveling through gap junctions

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

Phase 3 of nodal areas

A

L-type closing, VG-K re-opening to set the cell

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

Definite phases of nodal areas

A

4, 0 and 3.

Some textbooks will say there is a 2nd phase.

There is not a 1st phase at all.

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

AV node VRm and slope and threshold compared to SA node , and why?

A

Not as leaky to sodium and calcium in phase 4.

VRm is more negative than SA node, and less slope.

Thats why it’s slower if it’s the pacemaker.

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

HCN channels in the heart are found where?

A

Most in the SA

A lot but less in AV

Ventricles there’s hardly any, but they are there.

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

Real deep interior ventricular APs are

A

Pretty long, longer plateau phase

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

Repolarization is set quicker for epicardium than

A

Subendocardium

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

Are atrials pumping against high or low resistance?

A

Low

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

Atria APs are compared as

A

In between a fast and slow AP

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

SA node HR and how often does it generate an AP?

A

72 bpm; every 0.83 seconds

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

If we took all of the nervous influences away from SA node, it would generate a heart rate of ____.

If we add SNS activity ONLY:

A

110 bpm; 120bpm (up by 10bpm)

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

What has a greater affect on HR, SNS or PNS (vagal)

A

PNS is much stronger effect

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

Secondary pacemaker is ___ and it generates spontaneous APs at __________ per minute.

A

AV node; 40-60bpm

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

Other pacemaker system of heart not SA or AV node, and it will spontaneously generate APs at ____ per minute.

A

purkinje fibers which is conduction system of ventricles, and it will beat at 15-30bpm.

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

What is the conduction system of the heart specifically for other than the obvious generating APs for heart beat?

A

Coordinated timing of all of the muscle mass. Needs to be an orderly process for the signals that each take a defined amount of time.

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

Conduction system in right atria are called

A

3 internodal pathways (in between SA and AV node)
Anterior
middle
posterior

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

Anterior internodal pathway is and its also called?

A

a bundle or collection of tissue that will conduct signals to left atrial pathway

Interatria bundle or bachman’s bundle

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

Time for AP to go from SA to AV node via internodal pathway

A

.03 seconds

3/100ths of a second

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

Time for AP to go from node to right atrial muscle to depolarize

A

0.07

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

Time for AP to go from node to left atrial muscle to depolarize

A

0.09

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

How long is the duration of the P-wave and what is it

A

0.09

time for all of the atria to depolarize

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

Why does it take longer for AP to reach outside of left atria?

A

no specialized conduction tissue, has to go through myofibrils

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

Time for a perfectly healthy heart for an AP to go from SA to the entire heart including ventricles?

A

0.22 seconds

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

Delay at AV node that causes holdup is due to

A

Delays so the atrials can contract and fill ventricles before AP goes to ventricles and contracts them to eject blood

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

If there are extra action potentials, what can fix that?

A

The delay of the AV node can help reset.

AV node acts as a filter

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

Why is there a delay in AV node? (physically)

A

fatty and cells don’t have many gap junctions, causing AP to take longer to travel.

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

Delay time of AV node

A

0.12 seconds

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

Delay in bundle of HIS is how long

A

.01

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

Total time for AP to get from SA node to each of main bundle branches is

A

0.16 seconds

.03 internodal

.12 delay in AV node
.01 delay in bundle of HIS

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

After an AP from SA node (P-wave), how long will it take QRS to start?

A

0.16 seconds

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

Where does QRS start?

A

Main (left and right) bundle branches in the interventricular septum

39
Q

If APs hit AV node while its in complete refractory period, will it generate AP?

A

no.

40
Q

Direction of electron movement during depolarization of ventricles

A

toward left foot at 59 degrees on average

41
Q

0 degrees is considered to be

A

horizontal

42
Q

If the put the electrodes closer to heart, the deflections will appear

A

much larger.

43
Q

QT interval is measuring

A

length of time that depolarization happens in ventricular tissue.

44
Q

T-wave is

A

Ventricles repolarizing

45
Q

P-wave is the

A

SA node generating AP

46
Q

SA node length and height

A

positive deflection that is 2 and a half small boxes long and tall

47
Q

If you have an inverted P-wave, that means

A

the APs are starting outside the SA node

48
Q

If you have a peaked P-wave

A

Hypertrophy or stretched out right atria

more tissue we have, higher magnitude of deflection

49
Q

If you have a long P-wave

A

Likely an issue with the left atria to be depolarized

Left atria stretched out

50
Q

A way to remember peaked and long p-wave issues

A

Height - Right
Long - Left

51
Q

If there is a really big problem with left atria, it can have a

A

double hump, its an electrical block

52
Q

Q-wave

A

negative deflection before an R-wave

Not all leads will have a Q-wave, depending on orientation.

53
Q

R-wave

A

Positive deflection that is the depolarization of the ventricles

54
Q

PR interval

A

Period of time between P-wave and start of R-wave

Dont call it PQ cause not everyone has a Q wave

55
Q

PR interval length

A

0.16 seconds

56
Q

S-wave

A

neg deflection after R wave

57
Q

How long does it take depolarize last tip of lateral wall of left ventricle?

A

.06 seconds between bundle branch and lateral wall of left ventricle, ideallyHo

58
Q

How long is QRS?

A

0.06 seconds.

Its the .22 seconds total of heart, minus the .16 (time of nodal tissue and total delays)

59
Q

If the Lateral wall of left ventricle shows .39 seconds to depolarize, and the SA/AV node takes .21 seconds to depolarize + the delay, how long did it take the ventricles to depolarize? What would this be on the EKG?

A

.18 seconds

.39 - .21 = .18

QRS complex

60
Q

Height of QRS

A

Net deflection of 1.5 mV

+1 to upside, bottom side of 0.3

roughly 1.5 mV and 3 large boxes

61
Q

Magnitude of deflection of QRS complex is measured how

A

how far it goes up above baseline + how far it goes below baseline = total magnitude of deflection

62
Q

If we have a really large QRS complex, it is due to

A

electrodes really close to heart, or heart tissue is massive (hypertrophy)

Hypertrophy would also make it longer

63
Q

What would prolong length but not height of QRS?

A

dilated cardiomyopathy.

Tissue isnt thicker, but it is stretched out and makes it take longer.

64
Q

Where does atria repolarize?

A

its hidden by large size of QRS, but it looks like it would be right around S-wave

65
Q

At the very end of QRS complex, or end of S-wave, all of the ventricular tissue is

A

depolarized

66
Q

Reference point for figuring out injury or infarct

A

J-point or isoelectric point

Reference point at end of QRS complex (end of S-wave)

67
Q

After the T-wave, all of the ventricular muscle should be

A

reset/repolarized. Except the unhealthy tissue.

68
Q

What would area after T-wave look like if there is unhealthy tissue?

A

Tissue that didnt repolarize and it would show some funky current and generating electrical activity

compare it to J-point

69
Q

QT interval what is it and how long is it

A

time between start of depolarization and time that all the tissue is repolarized

.25 - .35 seconds

70
Q

.25 - .35 seconds (QT interval) is the duration of

A

endocardial fast action potentials

71
Q

ST interval area can show

A

areas of injury or infarcts

not the specific time, but if there is funky currents

72
Q

Why is the T-wave upward deflection

A

Repolarization in opposite direction of depolarization.

Its the repolarization from superficial to deep

depolarization is deep to superficial

73
Q

If we needed a faster heart rate, heart will shorten up

A

ST segment, QT interval, and of course time in between beats

Ventricles adjust too by speeding up process of pumping and resetting

74
Q

Lusitropy

A

Resetting/repolarizing of the ventricle

75
Q

Positive lusitropy

A

Repolarizes ventricle faster than it normally does

76
Q

negative lusitropy

A

Repolarizes ventricle slower than it normally does

77
Q

Inotropy

A

stronger heart beat from more calcium coming into heart/release from SR

78
Q

Chronotropy

A

Heart rate

79
Q

Dromotropy

A

Speed of conduction of action potentials

80
Q

What is dromotropy dependent on?

A

Sodium currents and how much/how fast we have them coming into heart cells

81
Q

RR interval

A

time in between R waves

82
Q

Typical RR interval is

A

0.83 seconds

83
Q

60 divided by 0.83 = what is it?

A

Heart rate.

72bpm

84
Q

What if there RR interval is .91 seconds?

.43?

A

66bpm

140bpm

85
Q

A higher RR interval will result in ________.

A lower RR interval will result in _______.

A

Lower heart rate

Higher heart rate

86
Q

Each big box is __ mV

A

0.5

87
Q

Each small box is ___ mV and ___ seconds

A

0.1 mV and .04 seconds

88
Q

old school eKG machines fed the paper at how fast?

A

25mm per second

89
Q

How many big boxes in one second? How many seconds per box?

A

5 big boxes.

0.2

90
Q

Cardiac refractory period

A

time after an AP for the heart to reset itself

91
Q

Early premature contraction during refractory period

A

will result in smaller force of contraction, when it contracts before refractory period is over

92
Q

Where is the relative refractory period?

A

Very bottom of relative refractory period

If AP starts here, it will still generate contraction, just weaker (early premature contraction)

93
Q

A later premature contraction will

A

still contract the same strength

94
Q

Absolute refractory period

A

halfway down refractory period, will not elicit much of a contraction, if any at all.

A&P 1 (34 decks)

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