MEDICAL INSTRUMENTATION 1

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MEDICAL INSTRUMENTATION 1
Nerve Cell Membrane
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Introduction
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3
Nerve Cell
Up to 1 meter
25um
1um
Axon
Dendrite
Axon Termination
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Nerve Cell
Sensary Nerve
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HD??
DVD ??
Motor Nerve
D/A
player
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Membrane
Extracellular Fluid
Na
Intracellular Fluid
Na
Cl-
Cl-
K
K
K
Na

• Membrane ??? ????
• ????? ??
• ??? ???? Alive
• ?? ??? ?? ?????
• ???? ?? ? ??? ??.
• ?, ??? ???? ???? ?!
• Diffusion ? ??? Energy ??.

Na , K pump ????? ???? Energy(ATP)
Glucose O2 Energy?. ?? ????? ?? ??
?? ??(Glucose) , ?(O2)???
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Insulating Membrane
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Insulating membrane
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Na
Na
Cl-
Cl-
V 0
??
??
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Permeable Membrane
Membrane is permeable to both Na Cl-
?? ????? ??, ??? ??? ??? Diffusion? ??,
Na
Na
Cl-
Cl-
V 0
??
??
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Semi-permeable Membrane
Semi-persmeable Membrane (Only to Na)
Na
Na
Cl-
Cl-
Dynamic Equilibrium
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Analysis

• ??? ?? ??? ?
• ??? ( Electric Field ?? )
• ?? ?

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??) P/N - JUNCTION
P?
N?
??? ??? ????. Na, Cl- ? ? ??? ?
??. Pn-junction?? ??? ??? ? ??? ???? ? ????.
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Nernst Equation
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Nernst Equation
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Nernst Equation
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123p ?4.1?? ??
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Z? n? ??? ??? ? ?? ???? ????.
123p ?4.1? ??
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123p ?4.2?? ??
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E ?? ?? ??? ???? 0?? ???? ???? P ?? ???
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The Active State
Repolarization
Vo1
tt1
t
D1
D2
Depolarization
Hyperpolarization
tt2
Vo2
t2
t1
t
-60mV
Resting Membrane Potential (RMP)
tD
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??) Micropipet
Microelectrode Puller
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The Active Potential
Vo
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Membrane conductance (membrane permeability)
0
-20
-40
VTH Threshold Voltage
?? VTH???? ???? Na, K? conductance? ??? Depol.
Repol. ?
-60
Abstract Refractory Period
Relative Refractory Period
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Saturation
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Nerve Conduction Velocity
Nerve Conductance Velocity(NCV) ?? m/s (
40m/s, 90m/s )
t?
2m
t0, tickling
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Nerve Conduction Velocity
Resting
Na - K pump
Na
K
K
Depol.
Na
Na
Repol.
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Nerve Conduction Velocity
Refractory Period
NCV ?
NCV ?
22
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