Brainscape's Knowledge GenomeTM

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


See full index

NPTE Biophysical Agents > Electrical Agents > Flashcards

Electrical Agents Flashcards

1
Q

Resting membrane potential - cell membrane is more permeable to

A

potassium compared to sodium and negatively charged proteins (anions)

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

Electrical potential is generated across the cell membrane due to

A

higher concentration of K and anions on the inside relative to concentration of Na on outside

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

Resting membrane potential is maintained by

A

active Na/K pump that takes in K and extrudes Na

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

Action potential - a stimulus causes the cell membrane to become

A

more permeable to Na ions

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

An action potential is generated when

A

the influx of Na causes a reduction in resting membrane potential which occurs slowly at first
this reduction in membrane potential is called depolarization

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

During depolarization, transmembrane potential is where

A

can be as high as+35 mV

a positive charge is generated inside the cell and a negative charge outside the cell is produced

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

Repolarization - what happens

A

K channels are fully open at about the time that the Na are closed and K rushes out of the cell making the membrane potential more negative

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

Hyperpolarization - what happens

A

K channels stay open long enough to repolarize the membrane

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

Strength-duration curve: Rheobase

A

the intensity of the current with a long duration stimulus required to produce a minimum muscle contraction

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

Strength duration curve: Chronaxie

A

the pulse duration of the stimulus at twice the rheobase intensity

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

Motor point

A

An area of greatest excitability on the skin surface in which a small amount of current generates a muscle response

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

In an innervated muscle, the motor point is located

A

at or near where the motor nerve enters the muscle, usually over the mm belly

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

In denervated muscle, the motor point is located

A

over the muscle distally toward the insertion

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

The current has what relationship with voltage

A

directly related

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

The current has what relationship with resistance

A

inverse relationship

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

Inverse of resistance is called

A

conductance

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

Monophasic wave forms

A

Direct or galvanic
A unidirectional flow of charged particles
Current flow in one direction for a finite period
All either above or below baseline

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

Biphasic wave forms

A

alternating current
a bidirectional flow of charged particles
1/2 the cycle above baseline, 1/2 below

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

Polyphasic wave forms

A

biphasic current modified to produce three or more phases in a single pulse
medium freq and can be Russian or IFC

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

Current modulation - Surge mode

A

a gradual increase and decrease in the current intensity over a finite period of time

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

Current modulation - Ramped mode

A

a time period with a gradual rise of the current intensity which is maintained at a selected level for a given period or time followed by a gradual or abrupt decline in intensity

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

Contraindications to Estim

A

Anywhere that pt has pacemaker or electronic device
Over or in area of carotid sinus, thromb, eyes, thoracic area, phrenic, low back with preg
Presence of active bleeding or infection
Superficial metal implants
Pharyngeal/Laryngeal mm

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

Guidelines - Electrode size

A

Two leads are required to complete the current circuit

One active and one inactive (or dispersive)

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

Guidelines - current density

A

relative to electrode size
A given current intensity passing through the smaller active electrode produces high current density and thus a strong stimulus while same current is perceived as less intensive under a larger dispersive electrode

25
Q

Active electrode is usually placed over

A

the treatment site - motor point

26
Q

Unipolar/Monopolar placement

A

one electrode or multiple bifurcated active electrodes placed over a treatment area

27
Q

Bipolar placement

A

Equal sized active and dispersive electrodes on same mm group or in same tx area

28
Q

Space between active and dispersive should be

A

at least the diameter of the active electrode

29
Q

Ionto - what is it

A

application of a continuous direct current to transport medicinal agents through the skin or mucous membranes for therapeutic purposes

30
Q

Ionto - polar effects - positive ions move toward

A

negative pole (cathode) where a secondary alkaline reaction (NaOH) occurs

31
Q

Ionto - polar effects - negative ions move toward

A

the positive pole (anode) where an acid is produced (HCl)

32
Q

Ionto - the number of ions transferred through the skin is directly related to the

A

duration of treatment
current density
concentration of ions in the solution

33
Q

Characteristics of ionto

A

direct current

max intensity of 4-5 mA

34
Q

TENS is what

A

designed to provide afferent stimulation for pain management

35
Q

TENS - physiological effects

A

pain modulation through activation of central inhibiiton of pain transmission
Large diameter A beta fibers activate inhibitory interneurons producing inhibiiton of smaller A delta and C fibers (pain fibers)

36
Q

TENS - characteristics - wave form

A

typically asymmetrical biphasic with a zero net direct current component
Current can be continuous, pulsatile, or burst

37
Q

conventional high rate TENS - amplitude -

A

comfortable tingling sensation, paresthesia, no mm response

gate theory

38
Q

conventional high rate TENS - pulse rate

A

50-80 pps

39
Q

conventional high rate TENS - pulse duration

A

50-100 usec

40
Q

conventional high rate TENS - mode

A

continuous

41
Q

High voltage pulsed galvanic stimulation is what

A

high voltage pulsed current - typically monophasic, twin peaked pulses of short duration

42
Q

ES characteristics of HVPC - wave form

A

paired monophasic, with instantaneous rise and exponential fall of current

43
Q

ES characteristics of HVPC - current

A

continuous, surged, or interrupted pulsatile current

44
Q

ES HPVC - procedure of how it works

A

Intact skin surface is neg with respect to deeper epidermal layers
Injruy to skin develops pos potentials initially and neg potentials with healing process
Absent or insufficient pos potentials retard tissue regeneration
Addition of pos potentials may accelerate or promote healing

45
Q

HPVC - wound healing parameters

A 
Amplictude - analgesic
Pulse rate - 50-200 pps
Pulse duration - 20-100 usec
Mode - continuous
Tx time - 20-60 min
46
Q

Medium frequency current ES is what

A

freq in range of 2000-5000 pps that are modulated to produce physiologically applied freq
Russian and IFC

47
Q

Russian current description

A

a 2500 Hz which is interrupted for 10 ms at 10 ms intervals, producing 50 10 ms bursts per second

48
Q

ES characteristics with Russian - wave form

A

wave form is polyphasic, sinusoidal

49
Q

Russian - parameters

A

Amplitude - mm contraction
Pulse rate 50-70
Pulse duration 150-200 or 50% duty cycle
Mode - interrupted, ramp 1-5 sec, duty cycle 1:5

50
Q

Russian - mm spasm protocol

A

1:1 ratio

51
Q

IFC - description

A

characterized by crossing of two sinusoidal waves with similar amplitudes but different carrier freq that interfere with one another to generate an amplitude modulated beat freq

52
Q

IFC - constructive interference

A

two waves are in phase, the sum of superimposed wave is large

53
Q

IFC - destructive interference

A

the sum of the two waves is zero when the waves are 180 degrees out of phase

54
Q

IFC - beat freq

A

resultant freq produced b the two freq going in and out of phase
Can be constant (both freq are fixed) or can be variable (where one is fixed and other varies in freq)

55
Q

Functional ES

A

encompasses wide rage of stimulator units and techniques for disuse atrophy, impaired ROM, mm spasm, mm re ed, and spasticity management
FES also called NMES

56
Q

ES characteristics of FES - wave form

A

asymmetrical biphasic square

current is iterrupted pulsatile current

57
Q

FES - parameters if using for shoulder subluxation after CVA

A

Amp: tetanic mm conraction
Pulse rate - 12 to 25 pps
Tx time - 15 to 30 m
On/off ratio of 1:3

58
Q

EMG biofeedback

A

electronic instrument used to measure motor unit action potentials generated by active mm
signals are detected, amplified, and converted into audiovisual signals that are used to reinforce voluntary control

NPTE Biophysical Agents (3 decks)

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