Cathodal vs Anodal Electrical Stimulation

[emdezla]

Hello everyone,

I am studying at the moment electrical stimulation of nerve fibers. I encountered this image which compares cathodal and anodal stimulation but illustrating the anodal block ocurring with cathode current. But I don't really get the point of the image, could someone clarify it to me?

I leave you here the description of the image:

Current-distance relationship for unmyelinated fibers. Excitation occurs for points lying in the shaded region. For cathodal stimulation, a minimum distance arises at the point where anodal block prevents the escape of the action impulse. For anodal stimulation, block does not occur; thus there is no lower limit on the source-fiber distance. The inner scales are for a fiber diameter of 9.6 µm, and the outer for a diameter of 38.4 µm. (An examination of Equations 21.10 and 21.13 shows that scaling the excitation with respect to both current strength, source-fiber distance, and fiber diameter leaves the solution unchanged.) (From Rattay, 1987.)

Thank you very much.

 

[TeethWhitener]

What exactly are you confused by? Do you understand the concept of anodal block? Or is it something more specific about the graph?