Intro to EPA

Question 1

Conduction current flows in ________.

Answer 1

conductors

Question 2

Convection current flows in ______ or ____.

Answer 2

fluids; gases

Question 3

Current is measured in ?

Answer 3

amperes

Question 4

Conduction current = _________ material in which the outer shell electrons are free to move between the fixed atoms.

Answer 4

crystalline

Question 5

Convection current flows via the movement of ____.

Answer 5

ions

Question 6

Positive ions = ?

Answer 6

cations

Question 7

Negative ions = ?

Answer 7

anions

Question 8

You need an ______ between conduction current and convection current.

Answer 8

interface

Question 9

Current flows in electrolyte solutions or plasma in which direction(s)?

Answer 9

Both from positive to negative and vice versa

Question 10

_______ = the electric charge carried by a current of one ampere, flowing for one second

Answer 10

coulomb

Question 11

______ = the basic unit of measured charge

Answer 11

coulomb

Question 12

______ = the rate of flow of current; current intensity

Answer 12

ampere

Question 13

1 ampere = ?

Answer 13

1 C/s

Question 14

______ = the measure of energy difference between two physical points

Answer 14

volt

Question 15

1V = ?

Answer 15

1J/C

Question 16

What is resistance measured in?

Answer 16

Ohms

Question 17

Does dry or wet epidermis have higher resistance?

Answer 17

Dry

Question 18

What is Ohm’s law?

Answer 18

V = IxR

Question 19

_____ = the rate of converting energy

Answer 19

watt

Question 20

1W = ?

Answer 20

1 J/sec

Question 21

What two things does current density depend on?

Answer 21

1. amount of current

2. cross section of the wire / area of electrode

Question 22

What are 3 ways to minimize current density in treatment?

Answer 22

1. adequate electrode size
2. electrodes are in good condition
3. lowest intensity for therapeutic benefit

Question 23

A _______ = two conductors separated by an insulator

Answer 23

capacitor

Question 24

_______ = stores electric charge, and current frequency determines resistance to current flow

Answer 24

capacitor

Question 25

Dry epidermis impedes the passage of electric current, and it is a combination of what 3 things?

Answer 25

1. Ohmic resistance 2. Capacitive reactance 3. Inductive reactance (minimally important)

Question 26

_____ _______ = a materials opposition to the flow of electric current, measured in ohms

Answer 26

ohmic resistance

Question 27

_____ _______ = the opposition to current flow provided for a capacitor, is measured in ohms and varies inversely with frequency

Answer 27

capacitive reactance

Question 28

What 3 things does skin resistance depend on?

Answer 28

1. Dry or wet skin 2. Pulse duration 3. Current intensity

Question 29

What current has the highest impedance?

Answer 29

Direct current

Question 30

Do you want electrical devices with constant voltage or constant current?

Answer 30

constant VOLTAGE!

Question 31

________ = formation of new chemical compounds

Answer 31

electrochemical

Question 32

________ = stimulation of excitable tissue

Answer 32

electrophysical

Question 33

________ = production of heat

Answer 33

electrothermal

Question 34

Electrochemical occurs with _________ current only

Answer 34

unidirectional

Question 35

Electrochemical charges can cause blistering or chemical burns (T/F)?

Answer 35

TRUE

Question 36

Electrophysical effects are caused by _______ movement.

Answer 36

ionic

Question 37

Ionic movement in ________ effects causes indirect responses such as muscle contraction, activate endogenous analgesic mechanisms, vascular responses

Answer 37

electrophysical

Question 38

_________ = heating caused by friction from movement of charged particles in a conductive medium

Answer 38

electrothermal

Question 39

_______ _____ = electrical stimulation results in the movement of ions

Answer 39

cellular signalling

Question 40

What are 4 cellular effects observed in response to applied electric current?

Answer 40

1. enhanced ATP synthesis 2. DNA synthesis 3. Facilitating activity of other enzymes 4. Cytokine release

Question 41

What are 3 types of current?

Answer 41

1. direct 2. alternating 3. pulsed

Question 42

What are 3 fundamental questions before treatment?

Answer 42

1. what effect is intended and can this treatment achieve this effect? 2. is it safe? 3. is this the best method of treatment to achieve this effect?

Question 43

What are 4 clinical applications or therapeutic modalities?

Answer 43

1. Modulation of pain 2. Alteration of skeletal muscle performance (facilitation and inhibition) 3. Decrease inflammation and facilitating tissue healing 4. Increase tissue extensibility

Question 44

Tissue damage from passage of electric currents can occur in what 3 ways?

Answer 44

1. direct of phasic currents can cause chemical burns 2. currents that stimulate nerve of muscle (powerful or prolonged contraction of muscles) 3. high current density can cause burns through tissue heating

Question 45

Chemical burns can occur using direct and alternating current (T/F).

Answer 45

FALSE ; just DC; AC would not allow the build up of new compounds under each electrode

Question 46

_____shock = current passes into body through skin

Answer 46

macro

Question 47

___mA of current may be fatal in macroshock

Answer 47

100

Question 48

___shock = current passes directly to heart

Answer 48

micro

Question 49

__uA may cause ventricular fibrillation

Answer 49

20 (micro?)

Question 50

In macroshock, what is important is the total electric charge - this includes both the _____ and ____ of the current (as well as path it travels through body)

Answer 50

amplitude; duration

Question 51

In macroshock, ____ is the primary variable that determines the severity of the shock.

Answer 51

current

Question 52

All non-battery therapeutic devices must use a ___pin plug.

Answer 52

3