Brainscape's Knowledge GenomeTM

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


See full index

Physiology > Cardiac Electrophysiology > Flashcards

Cardiac Electrophysiology Flashcards

1
Q

What is commotio cardis?

A

sudden blunt impact to the chest that causes sudden cardiac arrest

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

What is the intrinsic heart rate?

A

no neural input: 100 bpm

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

What is the meximum effective heart heart?

A

180 bpm

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

What is the bpm for tachycardia?

A

greater than 100

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

What is the bpm for bradycardia?

A

less than 60

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

What is the dynamic range?

A

20 - 250 bpm

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

What does an ECG measure?

A

cardiac action potential; events happen quickly

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

What occurs during a P wave?

A

atria depolarize

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

What happens during a QRS wave?

A

ventricles depolarize

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

What happens during the T wave?

A

ventricles repolarize

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

Does ventricular or atrial AP last longer?

A

ventricular has longer duration

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

What waves are considered ventricular AP?

A

QRS and T wave

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

What waves are considered atrial AP?

A

P wave

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

What are the atrial components?

A
  • sino-atrial node
  • arterial internodal pathways
  • atrial ventricular node
  • Bachman’s bundle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the sinal-atrial node?

A
  • initial packemaker region
  • origin of cardiac AP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the atrial internodal pathways?

A

Carries sino-atrial node to AV node and spreads AP across the atrial myocardium

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

What is the atrial ventricular node?

A
  • passage of atrial AP to ventricular AP
  • conductance slowed; enables atrium time to contract and fill ventricles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is Bachman’s bundle?

A

passage of right atrial AP to left atrial AP

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

What are the ventricular components?

A
  • AV bundle of HIS
  • left and right bundle branches
  • Purkinje fibers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the AV bundle?

A

secondary pacemaker region

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

What is the function of the left and right bundle branches?

A
  • conducts AV node AP through cardiac septum along left and right branches
  • separate left and right ventricular pathways
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What in the purpose of Purkinje fibers?

A
  • conducts AP throughout ventricular myocardial tissue
  • tertiary packemaker site
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the path of AP conduction velocities?

A

SA node -> internodal atrial fibers -> atrial myocardium -> junction ->AV node -> bundle of HIS -> Purkinje fibers ->ventricular myocardium

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

What are the factors that affect current flow?

A
  • # of cell-cell gap junctions
  • cell diameter: small= small conduction velocity; large= large conuction velocity
  • cell alignment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the RR intervak in cardiac excitation?

A

time from one R wave to the next

inverse= heart rate

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

What is the RR interval in cardiac excitation?

A

time from one R wave to the next

inverse= heart rate

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

What is the PR interval in cardiac excitation?

A

start of atrial depolarization to ventricular depolarization

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

What is the QRS interval in cardiac excitation?

A

time ventricular depolarization occurs

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

What is the ST segment in cardiac excitation?

A

time after ventricular polarization

30
Q

What is the QT interval in cardiac excitation?

A

start of deplarization to end of repolarization

31
Q

What has a fast AP and is considered a conducting cell??

A
  • atrial muscle
  • ventricular muscle
  • bundle branch
  • Purkinje fibers
32
Q

What has slow AP and is considered a pacemaker cell?

A
  • SA node pacemaker
  • atrioventricular node
33
Q

What is the affect on ion channels during depolarization?

A

inward Na and Ca currents

34
Q

What is the affect on ion channels during repolarization/hyperpolarization?

A

outward K currents

35
Q

What happens in phase 0 of ion channels?

A
  • depolarization
  • activation of fast voltage gated Na and Ca channels
  • inward Na (Ina) and Ca (Ica) flux
36
Q

What happens in phase 1 of ion channels?

A
  • early repolarization
  • activation of a transient outward voltage gated K channel
  • outward K flux (Ito)
  • inactivation of Na channels
37
Q

What happens in phase 2 of ion channels?

A
  • plateau
  • activation of voltage gated Ca channels
  • activation of delayed rectifier K channels (Ikr and Iks)
  • inward Ca flux and outward K flux counteract each other
38
Q

What happens in phase 3 of ion channels?

A
  • late repolarization
  • activation of voltage gated Ca current
  • activation of delayed rectifier K channels
  • inward rectifier K channels (Ik1)
  • outward K flux
39
Q

What happens in phase 4 of ion channels?

A
  • diastolic resting potential
  • activated inward rectifier K channels
  • outward K influx (Ik1)
40
Q

What are the 3 states of voltage gated channels?

A
  • closed: NO ions flow through the channel pore
  • open (depolarization): ions flow through the channel pore based on electrochemical force
  • inactivated: NO ions flow through the channel pore
41
Q

How many subunits do voltage gated K channels have?

A

4 subunits with 6 transmembrane domains in each

42
Q

Where does ion selectivity occur?

A

in the pore, only allowing K to pass

43
Q

The transmembrane region has what sensor in what specific region?

A

voltage sensor in S4 region

44
Q

Outward currents include what channels?

A

voltage gated K channels and inward rectifier K channels

45
Q

How many subunits are required to form the ion channel in outward currents?

A

4 subunits

46
Q

Inward currents include what channels?

A

Na and voltage gated Ca channels

47
Q

How many subunits are required to form the ion channel in inward currents?

A

1 alpha subunit with 4 domains

48
Q

Inward currents are produced by what?

A

single polypeptide chain

49
Q

What is a pore region in inward currents?

A

one specifically allows Na to come through and another allows Ca to come through

50
Q

What is the similarity between cardiac and neuronal AP?

A

both fire overshooting all-or-none AP

51
Q

What is the difference between cardiac and neuronal AP?

A
  • duration of cardiac AP is longer than neuronal AP
52
Q

What is a refractory period?

A

period that causes enough time for heart to fill with blood before the next contraction

53
Q

What is the effective refractory period?

A

when the cell CANNOT fire another AP

54
Q

What is the relative refractory period?

A

cell CAN fire another AP but amplitude is reduced

55
Q

Both the effective and relative refractory periods are caused by what?

A

inactivation state of voltage gated Na or Ca channels

56
Q

What differerntiates pacemaker cells from ventricular cells?

A

pacemaker cells have:
* slower riding phase in phase 0
* no early repolarization pahse 1
* no plateau phas in phase 2
* slower depolarize in phase 4
* resting potential is more depolarized

57
Q

All cells express what specific channel?

A

If (funny)

58
Q

What is automaticity?

A

initiates heart beat

59
Q

What is rhythmicity?

A

regular pacemaking activity

60
Q

What is the dominant packemaker?

A

SA node

AV node is the backup

61
Q

What happens in phase 0 of slow pacemakers?

A

Ica: Ca current voltage dependent Ca channel

62
Q

What happens in phase 3 of slow pacemakers?

A

Ik: K current voltage-dependent K channel

63
Q

What happens in phase 4 of slow pacemakers?

A

If: pacemaker cureent cyclic-nucleotide gated Na channel

needed for automaticity

64
Q

What is the threshold potential?

A

membrane potential for triggering all or nothing AP

65
Q

What are the steps for altering automaticity and firing frequency?

A
  1. change in slope of phase 4
  2. hyperpolarization during phase 4
  3. change in threshold for firing
66
Q

What is the resting heart rate reduced by?

A

basal parasympathetic tone

67
Q

Innervation of nodal regions are predominantly what?

A

parasympathetic

68
Q

How does exercise affect the heart rate regulated by the autonomic nervous system?

A
  • reduces parasympathetic tone
  • increases sympathetic tone
  • increases HR and force of myocardial contraction
69
Q

How does sympathetic stimulation affect ion channels?

A

increase If, Ica, and Ik

70
Q

How does parasympathetic stimulation affect ion channels?

A
  • decrease If and Ica
  • increase Ik (Ach)

Physiology (9 decks)

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