Basic Principles of Electricity

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Basic Principles of Electricity
2011-02-19 21:59:16
Mod Test Two

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  1. When is E. Stim used in Physical Therapy
    • Treat neuromuscular conditions
    • Enhance local circulation
    • Promote tissue healing
    • Decrease pain
    • Increase ROM
  2. Define Electrical Current
    • Movement or flow of charged particles (electrons/ions) from one place to another
    • Amount of current depends on # of electrons/ions passing a given point per unit of time
  3. How is current messured
    • 1amp = 1 coulomb
    • Milliamp 1,000th mA
    • Microamp 1,000,000uA
  4. Define Electromotive Force
    • a difference in potential is established when the amount of charge at one end of the ciruit os greater thean the other end
    • The difference in potential is called volts
  5. Define Anode
    • Positvie side of the circuit
    • Attact negative charges
  6. Define Cathode
    • Negative end
    • Attracts positive
  7. How an action potention is created
    • Excitation occurs principally at the cathode
    • near cathode(-) field attracts Na (+) ions
    • decreases the positive charge on the outside of the membrane and leads to excitation
  8. What way does electrical current flow?
    elctrons flow from neg to pos
  9. Describe Direct Current
    • Constant unidiretional flow of electricity
    • Same charge the whole treatment
    • DC can induce chemical reaction in the body
    • Negative charge increases chance for burns
    • Positive is safer
  10. Describe Alternating Current
    • Changes it's direction of flow periodically
    • No net chemcial reactions occurs - safer
  11. Define Conductor
    material with less reistance and readily allow current to pass
  12. Define Insulator
    high resistnace and impede passage of current
  13. Resistance
    • current will take the path of least resistance
    • current does not create a unifor pathway through all tissue
    • Increases intestisty to get to nerves
    • Larger fibers are more easily stimulated (A-beta first)
  14. Describe Impedance
    • Resitance to Electrical Current
    • muscle 72-75% water
    • Fat 14-15%water
    • bone 5-16% water