Intro To Electrical Stim Part 1

Front 1

Charge (coulombs)

Back 1

Loss or gain of electrons

Front 2

Polarity: cathode (-), anode (+)

Back 2

Attraction/ repulsion forces = electric field

-Alkaline reactions under the cathode softens underlying tissues

Front 3

Attraction/repulsion forces

Back 3

Electric field

Front 4

What do Alkaline reactions under the cathode do what to tissues?

Back 4

Softens

Front 5

Voltage

Back 5

Driving force that moves electrons

Front 6

Measure of potential energy

Back 6

Voltage

Front 7

What are four main topics that define Principles of Electricity

Back 7

1. Charge

2. Polarity

3. Voltage

4. Conductors & insulators

Front 8

Conductors are?

Back 8

- Water

-Metals

-nerves

Front 9

Insulators are?

Back 9

-Rubber

-Plastic

-Fat

Front 10

What are the 3 main properties of electrically excitable cell

Back 10

1. Resting Membrane Potential (RMP)

2. Action Potential

3. Propagation of Action Potential

Front 11

What is the movement of the AP along the nerve called?

Back 11

Propagation

Front 12

What is the cell membrane more permeable to vs what?

Back 12

Potassium (K +) & Negatively-charged proteins (anions)

vs

Sodium (Na+)

Front 13

How is electrical potential generated across the cell membrane?

Back 13

Higher concentration of K+ & anions on the inside of the cell

Front 14

What is higher on the outside of the cell.

Back 14

Na+

Front 15

Polarity means it has a?

Back 15

POLL

Cathode (-) or Anode (+)

Front 16

What happens within the cell & outside the cell when the positively charged K+ diffuse from the cell?

Back 16

Negative charge inside

Positive charge outside

Front 17

Anion has what type of charge?

Back 17

Negative

Front 18

What type of charge does a Cation have?

Back 18

Positive

Front 19

What is the RMP for excitable cells?

Back 19

-60 mV to -90 mV

Front 20

How is RMP maintained by an active sodium potassium pump?

Back 20

Takes in K+ & extrudes Na+

Front 21

______ causes the cell membrane to become more permeable to Na+ ions.

Back 21

Stimulus (ex. electrical)

Front 22

How is a Action Potential (AP) generated?

Back 22

Influx of Na+ causes a reduction in RMP

-which occurs slowly at first.

Front 23

Depolarization

Back 23

Reduction in the RMP

Front 24

RMP stands for

Back 24

Resting membrane Postential

Front 25

What is the critical threshold level?

Back 25

-55 mv

Front 26

What happens when the transmembrane potential reaches a critical threshold level?

Back 26

The voltage-sensitive Na+ & K+ channels open widely

Front 27

How does diffusion occur? How is this possible due to the fact Na+ is positive & K + is positive

Back 27

Large negative proteins [anions] inside the cell

Front 28

Permeability to Na+ ______ & permeability to K+ _______

Back 28

-Increases RAPIDLY

-Increases SLOWLY

Front 29

How is a flow of ions produced?

Back 29

Depolarization --> A positive charge is generated inside the cell & a negative charge outside

Front 30

Transmembrane potential might rise as high as +35 mV during when?

Back 30

Depolarization

Front 31

When are K+ channels fully opened?

This causes what to happen?

Back 31

Na+ are closed

-K+ rushes rapidly out of the cell--> Transmembrane Potential progressively becomes more negative

Front 32

Repolarization

Back 32

When the transmembrane potential progressively more neg due to the K+ rushing out of the cell

Front 33

Hyperpolarization

Back 33

K+ channels remain open long enough to repolarize the membrane (10-20 mV < RMP)

Front 34

What happens at the end of the AP process?

Back 34

•K+ channels close & passive diffusion of the ions rapidly returns the RMP to its initial level.

Front 35

How does RMP return to its initial level?

Back 35

K+ channels close & passive diffusion of the ions

Front 36

How are successive depolarization in adjacent regions of the nerve, muscle, membranes triggered?

Back 36

Opening of the Na+ & K+ channels & voltage changes that produce an AP at one segment

Front 37

What is the process called when a AP movement occurs along the surface of the nerve or muscle cell.

Back 37

Propagation of the AP

Front 38

Amplitude means?

Back 38

How high you turn up the machine [current]

Front 39

Duration what are two meanings

Back 39

-Duration of the electrical impulse itself

-continuous or Pulse

-TIME

Front 40

Rate of rise

Back 40

-How fast the full strength comes on

ex. turning the radio on in your car very fast (fast rate of rise)

Front 41

Sequential Depolarization (eddy currents) generates what

Back 41

Movement of the AP along an unmyelinated nerve [slow]

Front 42

What is the pace of conduction in a small diameter fibers & why?

Back 42

Slow: greater internal resistance in the small fibers

-unmyelinated

Front 43

Where does myelinated nerve fibers, saltatory conduction occur?

Back 43

Discrete junctures (Nodes of Ranvier)

-in the myelin sheath which surrounds the nerve

-Saltortatory conduction

Front 44

AP is generated as ____ flow in at one location along an axon. [Step 2]

Back 44

Na+

Front 45

How is a AP initiated along a axon?

Back 45

Depolarization

[Step 3]

Front 46

How does repolarization occur?

Back 46

K+ ions flow out

Front 47

Amplitude or Intensity of the stimulus must be great enough to cause the membrane potential to be lowered sufficiently to reach what?

Back 47

Threshold levels

Front 48

Rheobase

Back 48

Minimum stimulation that will produce a minimum muscle contraction

Front 49

Duration of the individual stimulus must be long to do what?

Back 49

Depolarize the cell membrane

Front 50

Duration of Less than or equal to 1 ms does what to cells?

Back 50

Is sufficient to stimulate nerve cell membrane

BUT

TOO short to stimulate muscle cell membrane

Front 51

Rate of rise of the current to the peal intensity must be _____ enough to prevent ______

Back 51

-Rapid

-Accommodation

Front 52

Accommodation

Back 52

Rapid adjustment of the membrane to stimuli to prevent depolarization

Front 53

What does square wave deliver?

Back 53

Instantaneous rise

Front 54

Electro-diagnostic technique used to identify the state of injury of a motor nerve or muscle

Back 54

Strength-Duration Test

Front 55

What two things have rendered strength-duration testing obsolete?

Back 55

1. Nerve conduction velocity

2. EMG

Front 56

Pulse duration of the stimulus at twice the Rheobase intensity.

Back 56

Chronaxie

Front 57

Intensity of current, having a long duration stimulus, required to produce minimum muscle contraction.

Back 57

Rheobase

Front 58

What type of pulse with what type of intensity can depolarize sensory nerves?

Back 58

Short pulse duration ( 0.05 msec) with low intensities.

low intensities

Front 59

What represents the threshold for depolarization of a nerve fiber?

Back 59

Strength-Duration Curves

Front 60

Muscle & nerve respond in a what type of fashion?

Back 60

All-or-none

-no gradation of response

Front 61

Shape of the curve relates what two things, necessary to cause the tissue to depolarize?

Back 61

1. Intensity of electrical stimulus (STRENGTH)

2. Length of time (DURATION)

Front 62

Rheobase

Back 62

-minimum intensity of current necessary to cause tissue excitation when applied for a maximum duration

Front 63

Chronaxie

Back 63

-Length of time (duration) required for current of twice the intensity of the rheobase current to produce tissue excitation

Front 64

Name the type of fiber

-Aß

-A gamma

-C

Back 64

-sensory & -motor

-sensory

- pain nerve fibers

Front 65

The lower axis on strength-duration curves has what?

Back 65

Durations of several electrical simulators

Front 66

Corresponding intensities would be necessary to create a _____?

Back 66

Depolarizing stimulus for any of the nerve fibers

Front 67

What is a motor point?

Back 67

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

Front 68

Where is the motor point located in a innervated muscle?

Back 68

At or near where the motor nerve enters the muscles, usually over the muscle belly

Front 69

Where is the area of greatest excitability is located over where in DENERVATED muscle?

Back 69

Over the muscle, distally (insertion) area

Front 70

A low frequency pulse (1-10 pulses/sec) produces what?

Back 70

-A brief muscle twitch or muscle contraction w/ each stimulus

Front 71

How is a tetanic contractions occur?

Back 71

Increasing the number of stimuli (frequency) progressively fuses the individual muscle twitches to a point where the individual twitches are not discernible.

Front 72

How is tetany caused?

Back 72

-Disease or other conditions that increase the AP frequency

Front 73

AMPs

Back 73

rate of flow of electrons

Front 74

Involuntary contraction of muscles caused by disease.

Back 74

Tetany

Front 75

Blocking of the inhibition to the neurons that supply muscles, caused by disease tetanus is called what?

Back 75

Is called Muscle Cramps

- not classified as tetany

Front 76

Denervated Muscle contains what type of response

Back 76

Asynchronous or worm-like (vermicular) muscle

- worm like movement

Front 77

Movement of electrons through a conducting medium?

Back 77

Electrical Current

Front 78

Rate of flow of electrons

Back 78

Amperage

Front 79

Force that drives electrons through the conductive medium

Back 79

Voltage

Front 80

Coulomb's Law

Back 80

Opposites Attract

Likes Repel

Front 81

Property of a medium which opposes the flow of electrons?

Back 81

Resistance

Front 82

Ohm's Law expresses the relationship between what 3 things?

Back 82

1. Amperage

2. Voltage

3. Resistance

Front 83

Conductance

Back 83

Inverse of resistance

Front 84

Ohm's Law formula

Back 84

1. V= IR

2. I= V/R

3. R = V/I

-V is sometimes E

Front 85

What type of current was Ohm's law created?

Back 85

Direct current circuits

Front 86

Define

I-

R-

V-

Back 86

I- amps (intensity)

R- resistance Ω

V- Volts (sometimes E)

Front 87

When resistance increases current _____?

Back 87

Decreases

Front 88

Voltage current is defined as?

Back 88

Watts

-aka (power)

Front 89

Electron flow in amps is defined as?

Back 89

I: amps

Front 90

Voltage difference between 2 circuits points?

Back 90

E (volts)

Front 91

A circuit of 100 volts passes through a tissue w/ 5 ohmsof impedance.

How many Amps of current are they?

FORMULA

Back 91

Resistance = Volts x current (amps)

V/ Ω = A

Ω = V x A

100 V/5Ω = 20 A

V --> somestimes E

Front 92

100 volts & 5 ohms, how many amps of current are there?

Back 92

100 V/5Ω = 20 A

Front 93

Current is equal to?

Back 93

Voltage divided by resistance

A = V/R

Front 94

Wattage

Back 94

is the total electrical power produced by the circuit & is equal to current times voltage

W = A x V

Front 95

Watt is ____

Watt = _____ X ______

Back 95

Power

Amp X Volt

Front 96

Volt is _______ _________

Volt = ______ X _________

Back 96

Current

AMP X Ohm

Front 97

Amp is _______

Amp = Volt / Ohm

Back 97

Current

Volt X Ohm

Front 98

Which is easier to measure Amps or watts?

Back 98

Measuring amps

Front 99

Direct current

Back 99

Continuous unidirectional flow of electrons for at least 1 second

Front 100

Words that describe Direct current

Back 100

-Interrupted

-Reversed

-Interrupted/reverse

Front 101

Ampere (amp)

Back 101

a measure of the amount of electrically, called "current" in a circuit

Front 102

Voltage is measure of what?

Back 102

Force behind that electricity's motion

Front 103

Ohms is the resistance to?

Back 103

Current movement

Front 104

Alternating current

Back 104

Uninterrupted bidirectional flow of electrons, --> must change direction at least once per second.

Front 105

Pulse currents last how long?

Back 105

Less than 1 second

Front 106

If a current last longer than one second?

Back 106

DIRECT

Front 107

Pulsed current

Back 107

Unidirectional/ bidirectional flow of electrons that periodically ceases for short time period

Front 108

(Symmetrical or asymmetrical), phase duration, peak amplitude, bursts ==> describe what?

Back 108

Monophasic/ Biphasic (pulse)

Front 109

Words (currents) that describe Pulsed current

1. Duty cycle- Time modulation

2. Ramp time- Amplitude modulation

3.

4.

Back 109

3. Interphase/pulse intervals

4. Frequency (pps)

Front 110

What are the two types of Physiological responses to Electrical current?

Back 110

1. Electrochemical effects

2. Electrothermal effects

Front 111

Na+ to cathode (forms NaOH)

Cl- to anode (forms HCl)

-both combine with water

Back 111

Electrochemical effects

Front 112

Heat is a product of kinetic energy of molecules secondary to friction and vibration

Back 112

Electrothermal effect

Front 113

Electrochemical & Electrothermal effects are more concerned with what type of current?

Why?

Back 113

Direct current

-because tissue changes may occur

-minimal concern w/ AC or pulsed current

Front 114

What are more concerned w/ direct current

Back 114

Electrochemical & Electrothermal effects

Front 115

Electrophysical effects: Depolarization of cells interrupt what?

Back 115

Resting concentration gradients

Front 116

Electrophysical effects: ______ are depolarized 1st (-70 mV) then _____ (-90 mV)

Back 116

Nerves & Muscles

Front 117

Sensory response

Back 117

the pt. is feeling the stimulation butyou cant see it

Front 118

Motor Response

Back 118

when you can see it

Front 119

Noxious response

Back 119

painful

Front 120

Russian current

Back 120

Variation of AC used for strengthening muscles

(aka Burst modulation)

Front 121

High-volt pulsed current (HVPC) used for?

Back 121

-Pain modulation, tissue repair, wound healing

Front 122

Interferential current is primarily used for?

Back 122

Pain Modulation

Front 123

Low-intensity DC (microcurrent) used for?

Back 123

Tissue repair & wound healing

Front 124

Symmetrical/ Asymmetrical Biphasic PC is used for what two things?

Back 124

Muscle stimulation & Pain modulation

Front 125

What continues the AP propagation down the axon?

Back 125

Depolarization--Repolarization

Front 126

How does propagation of AP specifically occur. Hint exchange of what ions?

Back 126

Na+ & K + ion & current flow is concentrated --> impulse jumps from Node to Node, conducting nerve impulses.

Front 127

What type of pulse stimulates Motor nerves?

Back 127

Longer pulse durations (1 msec)

Front 128

What type of pulse & intensity stimulates Denervated muscle?

Back 128

Longpulse durations (> 10msec) with high intensities

Front 129

Example of a substance having HIGH resistance?

Which is what?

Back 129

Rubber

Insulator

Front 130

Example of a substance having LOW resistance? Which is what?

Back 130

Metal

Conductor

Front 131

In Ohm's Law the current is _____ proportional to the voltage & ________ proportional to resistance.

Back 131

Directly & Inversely

Front 132

What is a comprehensive measurement of power?

Back 132

Watts

Front 133

Another term for quantity of current?

Back 133

Amps

Front 134

What are the 3 levels of stimulation in order?

Back 134

1. Sensory

2. Motor

3. Noxious

Front 135

What are the different High-Volt Pulsed Current?

Back 135

-Continuous

-Reciprocating

-Surge

-Monophasic

Front 136

What are the 2 different Interferential currents?

Back 136

1) Quadripolar

2) Bipolar

Front 137

Low-intensity DC (microcurrent) does not stimulate what type of nerves?

Back 137

Sensory / Motor

Front 138

What two types of therapeutic currents are similar with little to no difference in effectiveness for muscle stimulation.

Back 138

Symmetrical biphasic PC vs. Russian