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

Exam 4 - Lecture 4 Flashcards

1
Q

Just inside fibrous pericardium is

A

Serious Pericardium, Parietal layer.

Directly connected to fibrous pericardium

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2
Q

Very very very thin stretchy layer that sits between parietal pericardium and the heart and what does it do?

A

Visceral layer

It is very clear and can hardly see it, allows heart to slide around easily

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3
Q

The more straight up and down phase 0 is, the more

A

fast sodium channels

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4
Q

Action potentials between 2 adjacent heart cells is done via

A

Gap junctions, mostly sodium, extremely low resistance and very fast.

Initiated by cells upstream

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5
Q

Downside of using gap junctions in heart

A

Bi-directional, can cause rogue electrical activity

APs can go backwards if hit at wrong time and cause alot of problems

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6
Q

What protects us from rogue action potentials in gap junctions in the heart?

A

Absolute refractory periods of cells in nodal tissue

Cell will not fire an AP in refractory period

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7
Q

3-lead EKG setup terms

A

Frontal/Coronal plane

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8
Q

Coronal or frontal plane can use

A

augmented leads or 3-lead ekg

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9
Q

the A in aVR, aVL means

A

augmented

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10
Q

Eyeball/sensor that is looking at current going towards or away from it is the

A

positive electrode

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11
Q

If current is going away from positive eyeball it will be

A

negative deflection

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12
Q

If current is going towards positive eyeball will be

A

positive deflection

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13
Q

Best lead that will see positive deflection in healthy patient

A

lead II on left foot/hip

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14
Q

Lead II eyeball on left foot/hip is positive or negative?

A

positive electrode

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15
Q

Lead I will have a positive or negative on left side of body? right?

A

positive left shoulder, negative right hand

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16
Q

There will always be _____ on left foot, _____ right arm, and _____ on left arm

A

2 positive electrodes (lead II and III); 2 negatives (Negative lead II, lead I); Positive lead I/negative lead III

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17
Q

Lead III will have a positive or negative electrode on left foot? left arm?

A

Positive left foot

Negative left arm

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18
Q

Which leads are on left foot? Number and charge

A

2 positives; Lead II and III

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19
Q

Which leads are on right arm? Number and charge

A

2 negatives; Lead II and I

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20
Q

Which leads are on left arm? Number and charge

A

Positive lead I, Negative lead III

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21
Q

In einthovens triangle, where are the leads on each side? charges?

A

Top side: lead I (left negative, right positive)
Left side: Lead II (Top negative, bottom positive)
Right side: Lead III (top negative, bottom positive)

Keep in mind, the bottom part of triangle is positive for both left and right, therefore the top is negative both sides. Lead I on top has left to right negative to positive.

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22
Q

what is the degree axis of the bottom side of Lead III of einthovens triangle?

top?

A

120 degrees

-60 degrees or +300 degrees

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23
Q

Who is einthoven

A

someone from europe, maybe a Duetsche scientist

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24
Q

What is the degree axis that the bottom side of Lead II of einthovens triangle? top?

A

60 degrees; -120 degrees, or +240 degrees

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25
Q

What is the degree axis of lead I?

A

Left side: 180
Right side: 0

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26
Q

Equipment needed for ekg

A

Lead selector/amplifier to amplify the signals

Chart recorder

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27
Q

Mean electrical axis of heart

A

59 degrees

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28
Q

Lead II angle is

A

60 degrees

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29
Q

Left axis deviation of MEA per this class? what about textbook def?

A

anything less than 59 degrees

<0 degrees

30
Q

Right axis deviation of MEA per this class? what about textbook def?

A

anything more than 59 degrees

> 90 degrees

31
Q

Normal deviation of MEA in this class? What about textbook definition?

A

59 degrees

0 to 90 degrees

32
Q

Left axis deviation means

A

the heart is tilted towards left arm (counter-clockwise)

33
Q

Right axis deviation means

A

The heart is tilted towards right arm (clockwise)

34
Q

What can swing axis one direction or other?

A

Bundle branch block, depending which side

35
Q

If you have COPD/huge lungs, what happens to axis?

A

Heart is pointing straight up and down, 90-degree axis

36
Q

If we took all the air out of our lungs, what happens to axis?

A

Left axis deviation

37
Q

If we took a huge deep breathe, what happens to axis?

A

Right axis deviation

38
Q

If textbook tells you the MEA is -90 degrees, it means its also

A

270 degrees

-90 would just mean counterclockwise from 0 degree

270 is the clockwise orientation from 0 degree

39
Q

Counter-clockwise means the degree is going to be

A

negative

40
Q

Clockwise means the degree is going to be

A

positive

41
Q

right wall of right ventricle will be ________, why?

A

thinner because it only pumps against the pulmonary circulation

42
Q

Left ventricle will be ____, why?

A

Thicker, thats why it takes longer time for action potential, also bc its furthest away from AV node, pumps against more pressure.

43
Q

Direction of depolarization, and starting at where?

A

Interventricular septum, goes up and around the ventricles to the inside of ventricle and outside of ventricle, and through the ventricle walls

44
Q

Why is P-wave positive?

A

Electrons are moving towards lead II during depolarization

45
Q

If repolarization started at SA node, what would the deflection be?

A

Negative

46
Q

The walls of atria are very _____ compared to ventricles

A

thin

47
Q

Why does atrial repolarization get hidden?

A

QRS of ventricles is much stronger, hiding the repolarization of smaller atrial muscles

48
Q

If we had action potentials being generated at AV node, what can happen to P-wave?

A

Negative deflection if AP is going backwards

49
Q

If the atrial t-wave was visible, would it be positive or negative?

A

Negative, because repolarization happens in same direction

50
Q

Einthovens law

A

magnitude of Lead I + lead III = magnitude of Lead II

51
Q

order of the 3 leads, what is the order of magnitude of EKG reading be in a healthy heart from largest to smallest?

A

Largest: Lead II
Middle: Lead III
Smallest: Lead I

52
Q

If the MEA is -150 degrees, what would be the magnitude detected in Lead III? Why?

A

0 degrees; its perfectly perpendicular to the 120 degree angle of lead III

53
Q

If the MEA is -90 degrees, what would be the magnitude detected in lead I?

A

0 degrees; its perfectly perpendicular to the 0 degree angle of lead I

54
Q

What are the angle degrees of Lead II? Positive and negative?

A

+60 degrees, + 240 degrees

-300 degrees, -120 degrees

55
Q

What are the angle degrees of Lead III? Positive and negative?

A

+120, + 300

-60, -240

56
Q

What are the angle degrees of lead I? Positive and negative?

A

0 and +180

0 and -180

57
Q

If the MEA is right axis deviated, whats the direction of deflection in lead I?

A

negative

58
Q

If the MEA is left axis deviated to 20 degrees, whats the direction of deflection for lead III?

A

negative deflection

59
Q

If the MEA is left axis deviated to 35 degrees, whats the direction of deflection for lead III?

A

Positive

60
Q

what degree range will all 3 leads be positive?

A

Lead III needs to be between >30 degrees and <210 degrees
Lead II needs to be between >-30 and <150 degrees
Lead I needs to be between >-90 and <90

Therefore, for all 3 to be positive, the angle of MEA needs to be between 31 and 89 degrees.

61
Q

What angle does Lead III need to be positive?

A

Lead III needs to be between >30 degrees and <210 degrees

62
Q

What angle does Lead II need to be positive?

A

Lead II needs to be between >-30 and <150 degrees

63
Q

What angle does Lead I need to be positive?

A

Lead I needs to be between >-90 and <90

64
Q

The net deflection in lead II will have to equal

A

the net deflection of lead I and III

einthovens law

65
Q

When using einthovens law, you MUST include the ___ deflection of each lead.

A

NET

subtract the negative deflection from the positive deflection for EACH lead!

66
Q

Once you get past 50% depolarization, how do the QRS waves and the arrow on destructured einthovens triangle react?

A

Still positive, but just less positive than before

arrow is shorter

67
Q

Is the endocardium depolarized or resting here?

A

Resting. Only the interventricular septum is depolarized at this exact moment.

68
Q

Where will the direction be towards? What will the leads read? What wave is this most likely?

A

Up towards left arm; lead III is very negative, lead II is very slightly negative, and lead I is still positive; likely S wave

69
Q

What are the leads reading right here?

A

Absolutely nothing. The heart is completely depolarized, there is no electron movement.

70
Q

Will lead I read an S-wave?

A

likely not, as lead I should be seeing positive current during S-wave.

71
Q

Bundle branches will depolarize the ______

A

little slice of tissue of LEFT ventricular side depolarizes first, then sending current toward right arm, creating that negative deflection shown in Q-wave

72
Q

Is the Q-wave positive or negative in lead III?

A

Positive, cause its moving to the right side of the body

A&P 1 (39 decks)

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