Final answer:
Nerve conduction velocity is least affected by stimulus intensity, as it primarily depends on the physical and physiological properties of nerve fibers, not the strength of a given stimulus.
Step-by-step explanation:
The student's question pertains to factors that influence nerve conduction velocity (CV). Among the provided options, nerve CV is least affected by stimulus intensity. Nerve conduction depends primarily on the physical properties of the nerve fibers themselves, such as the diameter of the axons and the presence of myelin sheaths, as well as physiological factors like temperature and age. Electric potentials in neurons, crucial for nerve conduction, result from ionic concentration differences across semipermeable membranes.
Specifically, increases in temperature can speed up conduction by enhancing ionic flow across the membrane, while age may lead to a gradual decline in conduction velocity. Electrode placement can influence the recorded measurements but does not directly affect the conduction velocity within the nerve fiber. Conversely, increases in stimulus intensity essentially increase the number of activated nerve fibers but do not change the speed at which an individual nerve fiber transmits its signal.