Brainscape's Knowledge GenomeTM

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


See full index

BSI Test 2 > Lecture 21 > Flashcards

Lecture 21 Flashcards

1
Q

Transmission through AV node is ______ due to smaller fibers and fewer gap junctions

A

Slower

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

True or false? Delay through AV node allows atria to contract before the ventricles contract.

A

True

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

Bundle of His conducts the action potential very fast or very slow?

A

Very Fast

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

Bundle of His is also know as what?

A

AV bundle

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

This is the natural pacemaker of the heart

A

SA Node

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

True or false? The SA node has contractile proteins

A

False

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

True or false? The SA node specialized muscle tissue

A

True

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

Fibers of SA node connect directly to what?

A

Regular myocardial fibers of atria

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

Action potential that is generated in SA node fibers travels immediately to atrial fibers and causes what to happen?

A

Atrial depolarization

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

The fibers of the SA node fire action potentials in rhythmic pattern of about 100 bpm via what mechanism?

A

Self-excitation

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

True or false? The fibers of the SA node are not permeable to Na+

A

False - the SA node fibers allow Na+ to leak in

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

True or false? Resting membrane potential of SA node is less negative in comparison to other fibers

A

True - resting membrane potential in SA node is -55 mV compared to -90 in other fibers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  • Depolarization up to threshold- mostly due to slow Na+ influx
  • Rapid depolarization- opening of L(“longlasting”)-type Ca++ channels
  • Repolarization- opening of K+ channels
A

Action potential of autoarythmic cell

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

Heart rate is set by the __ _______

A

SA node

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

_____ increases heart rate and contractility

A

SNS

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

_____ decreases heart rate and contractility

A

PNS

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

SNS releases what NT?

A

Norepinephrine

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

In SA node, Norepi _______ Na+ permeability, which increases restimg membrane potential, and increases rate of drift towards threshold

A

increases

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

In cardiac myocytes, Norepi _______ intracellular Ca++ concentration which _______ contractility

A

Increases, increases

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

Vagus nerve releases what NT?

A

acetylcholine

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

Acetylcholine release from Vagus nerve causes what?

A

Increase in permeability to K+, causing hyperpolarization

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

Hyperpolarization causes _____ rate of SA node firing and ______ excitability of AV jucntional fibers

A

Decreased, decreased

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

Hyperpolarization _____ intracellular Ca++ in monocytes, which decreases contractility

A

decreases

24
Q

During exercise are you using SNS or PNS more?

A

SNS

25
Q

At rest, are you using SNS or PNS more?

A

PNS

26
Q

What is phase 0 of an action potential of a contractile monocyte?

A

Opening of Na+ channels

27
Q

What is phase 1 of an action potential of a contractile monocyte?

A

K+ channels open and Na+ channels inactivate

28
Q

What is phase 2 of an action potential of a contractile monocyte?

A

L-type Ca++ channels open

29
Q

When does K+ outflow balance influx Ca++ causing repolarization plateau

A

When L-type Ca++ channels open

30
Q

What is responsible for initiation of contraction?

A

Influx of Ca++ from L-type Ca++ channels

31
Q

What is phase 3 of an action potential of a contractile monocyte?

A

More K+ channels open and Ca++ channels close

32
Q

What is phase 4 of an action potential of a contractile monocyte?

A
  • Na/K ATPase has in effect exchanged Na that entered in phase 0 for K+ that left in phase 2 & 3.
  • Ca++ is exported via various Ca++ pumps
33
Q

This long-lasting period prevents development of a tetanic contraction

A

Absolute refractory period (ARP)

34
Q

True or false? Any failure of the heart to relax fully would make it an ineffective pump.

A

True

35
Q

True or false? The SA node is the only pacemaker of the heart.

A

False

36
Q

AV node, Perkinje fibers, and atrial or ventricular muscle tissue are all ______ pacemakers

A

Abnormal or ectopic

37
Q

________ can result in abnormal sequence of contraction

A

Ectopic (abnormal) pacemakers

38
Q

This records the electrical activity within the myocardial muscle fibers

A

Electrocardiogram (EKG, ECG)

39
Q

P-wave represents what part of the cardiac cycle?

A

Atrial depolarization

40
Q

QRS complex represents what part of the cardiac cycle?

A

Ventricular depolrization

41
Q

T-wave represents what part of the cardiac cycle?

A

Ventricular repolarization

42
Q

P-Q or P-R interval represents what part of the cardiac cycle?

A

The rate of transmission through the AV node

43
Q

Q-T interval represents what part of the cardiac cycle?

A

Time between beginning of ventricular depolarization and end of ventricular repolarization

44
Q

S-T segment represents what part of the cardiac cycle?

A

Time between the end of ventricular depolarization and beginning of ventricular repolarization

45
Q

X axis of EKG represents what?

A

time

46
Q

Y axis of EKG represents what?

A

Voltage (mV)

47
Q

A wave of depolarization causes a wave of ______ charges within the myocardial muscle fibers

A

Positive

48
Q

Wave of repolarization causes a wave of ______ charges inside of myocardial muscle fibers

A

Negative

49
Q

If a wave of charges is moving toward a like charged electrode, there will be an ______ deflection (ex: positive charge moving toward positive electrode)

A

Upward deflection

50
Q

If a wave of charges is moving toward an opposite charged electrode, there will be an ______ deflection (ex: positive charge moving toward negative electrode)

A

Downward deflection

51
Q

Leads I, II, III, AVR, AVL, AVF are which type of leads?

A

6 limb leads

52
Q

Leads I, II, III are _____ leads

A

Bipolar leads – formed by two electrodes

53
Q

AVR, AVL, AVF are ____ leads

A

Unipolar leads – only one electrode placed, the other is common ground (negative)

54
Q

Leads V1-V6 are which type of leads?

A

6 chest leads

55
Q

In 6 chest leads, chest electrode is ____ and the back electrode is ___

A

Chest is positive and back is negative

56
Q

V1 QRS is negative or positive?

A

Negative

57
Q

V5 and V6 will be mostly negative or positive?

A

Positive

BSI Test 2 (12 decks)

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