Current and Charge Density
Is there a simple way to describe the
difference between current density and charge density? I have been
told that when stimulating a nerve, the charge density is more important.
Charge density is the net amount of charge within a volume: How many
charges are inside a box.
Current density is the rate of charge moving through a volume: How many
charges pass through a box in a given amount of time. Instead of using
a box, people will also just talk about a boundary area and ask how many
charges cross a boundary in a particular amount of time.
As you can see, these two ideas are intimately related to each other.
Now, as to how these relate to nerves and electric impulse transmission,
I am not an expert and do not know myself exactly.
Michael S. Pierce
Click here to return to the Physics Archives
Update: June 2012