Brainscape's Knowledge GenomeTM

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


See full index

Block 3 physiology > Cardiac Conduction > Flashcards

Cardiac Conduction Flashcards

1
Q

Where does cardiac contraction originate?

A

specialized cardiac pacemakers

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

Where does the cardiac contraction spread through?

A

through myocardium via myocardial conduction system

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

What is the SA node also called?

A

pacemaker

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

SA node: bpm

A

60-100 bpm

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

flow of cardiac contraction

A
  • SA node
  • Internodal atrial pathways
  • AV node
  • Bundle of His
  • Purkinje system
  • Intrinsic ventricular rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

AV node: bpm

A

40-60 bpm

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

intrinsic ventricular rate: bpm

A

<40 bpm

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

what happens after the pacemakers discharge?

A

the membrane potential returns to resting potential prior to discharging again

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

The ______ pacemaker conducting to the ventricles always sets the ventricular rate!

A

The fastest pacemaker conducting to the ventricles always sets the ventricular rate!

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

normal pacemaker sequence of rates

A

SA>AV>ventricular

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

areas of the heart which may serve as potential pacemakers

A

automaticity foci

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

_____ _______ determined by where pacing originates

A

Heart rhythm determined by where pacing originates

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

_______ foci of automaticity (originating outside of SA or AV nodes) can result in _________

A

Ectopic foci of automaticity (originating outside of SA or AV nodes) can result in arrhythmia

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

SA node origin = _____ rhythm

A

SA node origin = sinus rhythm

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

AV node origin = ____ rhythm

A

AV node origin = junctional rhythm

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

ventricle node origin = ____ rhythm

A

ventricle node origin = ventricular rhythm

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

Which nerves arise from spinal T2-4 segments?

A

postganglionic sympathetic nerves

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

What is the neurotransmitter for postganglionic sympathetic nerves?

A

norepinephrine

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

Where do the postganglionic nerves pass?

A

into the cardiac plexus to the SA node (right) and AV node (left)

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

What is in response to SNS stimulation?

A

adrenal epinephrine

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

effects of the Sympathetic NS

A
  • Increase SA node pacing
  • Increased AV node transmission
  • Increase myocardial contractility
22
Q

What nerve provides parasympathetic control?

A

vagus nerve

23
Q

What is the neurotransmitter for the vagus nerve?

A

acetylcholine

24
Q

effect of the Parasympathetic NS

A
  • decreased SA node pacing

- delayed signal transmission through AV node

25
Q

That does delayed signal transmission through the AV node cause?

A

increased refractory period

26
Q

speeds depolarization and increases discharge rate and force of contraction

A

norepinephrine stimulation in SNS

27
Q

hyperpolarizes and decreases rate of firing (no effect on contractility)

A

Ach stimulation in PNS

28
Q

_________ firing rate is also influenced by _____________ and _____.

A

Pacemaker firing rate is also influenced by temperature and drugs.

29
Q

What drug inhibits the PNS? Stimulates PNS?

A
  • atropine inhibits

- digitalis stimulates

30
Q

Which node normal sets the pace?

A

SA node

31
Q

AV node _____ transmission to bundle of _____

A

AV node SLOWS transmission to bundle of His

32
Q

What does slowing transmission to bundle of His do?

A

coordinates atrial and ventricular firing

33
Q

What wave is generated by activation of both atria?

A

P wave

34
Q

The interventricular ______ is activated first, from ____ to right, generating the __-wave

A

The interventricular septum is activated first, from left to right, generating the Q-wave

35
Q

What generates the R wave?

A

left and right ventricular wall activation

36
Q

What generates the S wave?

A

A few small areas of the ventricles are activated at a late stage

37
Q

What generates the T wave?

A

ventricular repolarization

38
Q

size of wave deflection that is either positive or negative

A

voltage

39
Q

Where is voltage greater?

A

in areas where there is more CONDUCTING muscle

40
Q

Is voltage greater in the ventricles or atria?

A

ventricles

41
Q

Is voltage greater in the right ventricles or left ventricle?

A

left ventricle

42
Q

Is voltage greater in areas of hypertrophy or normal mass of cardiac tissue?

A

areas of hypertrophy

43
Q

Does ischemic or dead tissue conduct voltage?

A

NO

44
Q

average direction of the combined electrical activity within the ventricles, affected by tissue mass, tissue conductivity

A

frontal axis/QRS axis

45
Q

causes of left axis deviation

A
  • Left ventricular hypertrophy
  • Left bundle branch block (LBBB)
  • Left anterior fasicular block (LAHB)
  • High diaphragm (ascites, pregnancy, abdominal mass)
  • Normal variants (especially elderly, obese)
  • Wolf-Parkinson-White syndrome (WPW)
46
Q

LVH - ___% of cases present with LAD

A

LVH - 50% of cases present with LAD

47
Q

Causes of right axis deviation

A
  • Right ventricular hypertrophy
  • Right bundle branch block (RBBB)
  • Left posterior fascicular block (LPHB)
  • Flat diaphragm (COPD)
  • Normal variants (especially young, thin)
48
Q

RVH - ____% cases present with RAD

A

RVH - 100% cases present with RAD

49
Q

indicated by the equiphasic precordial lead being either V3 or V4

A

normal horizontal axis

50
Q

indicated if equiphasic lead is V1 or V2

A

right axis rotation

51
Q

indicated if equiphasic lead is V5 or V6

A

left axis rotation

52
Q

Axis deviation (_____ plane) and rotation (_______ plane) is always ____ from infarction and ______ hypertrophy

A

Axis deviation (vertical plane) and rotation (horizontal plane) is always away from infarction and towards hypertrophy

Block 3 physiology (6 decks)

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