2006-08-08 07:20:56 · 3 answers · asked by Anonymous in Education & Reference ➔ Higher Education (University +)
The amount of current required to depolarize a nerve cell and get it to fire is on the order of 100 nanoamperes.
The capacitative current that flows into or out of a capacitor to effect a change in membrane potential of amplitude dV, is given by the equation:
Ic = C dV/dt (capacitative current = capacitance times the voltage change over time).
To make a back of the envelope calculation, let's stipulate an instantaneous change in voltage of 100 mV (i.e. dt=0; this gets rid of the time variable and simplifies the equation to:
Ic=C dv (capacitative current = capacitance times the change in voltage (basically a variation on Ohm's law where capacitance substitutes for resistance).
The generally accepted value for membrane capacitance (C) is 1 microfarad per square centimeter.
The voltage change is 0.1 volts (dV).
Plugging those numbers into the formula, yields a capacitative current of 100 nanoamperes (1 x 10 -7 amperes).
2006-08-08 07:37:16 · answer #1 · answered by Answers1 6 · 0⤊ 0⤋
The human body has no amperes. Amperes is a unit of measure of the flow of electricity.
2006-08-08 14:29:07 · answer #2 · answered by pappy 6 · 0⤊ 0⤋
Weeeellllll, 0.02A can kill under the worst conditions, so it's gonna be small!
2006-08-08 14:25:38 · answer #3 · answered by Anonymous · 0⤊ 0⤋