Question

In which of the following conditions would you most reasonably expect to generate the most tension in a single muscle fiber? assume otherwise equal conditions.

a. when a motor neuron generates a high frequency of action potentials.
b. when the maximum amount of acetylcholinesterase is active.
c. when the muscle fiber is at its longest possible length before breaking (thin filament pulled past end of thick filament).
d. when the motor unit is stimulated to twitch.

Answer 1

The most tension in a muscle fiber is generated when a motor neuron produces a high frequency of action potentials, which can cause summation and tetanus, leading to maximal muscle tension without any relaxation phase. Therefore correct option is A

Step-by-step explanation:

The question is asking in which condition would you expect to generate the most tension in a single muscle fiber. The most tension within a muscle fiber would be generated when a motor neuron generates a high frequency of action potentials. This is because high-frequency stimulation can lead to summation and tetanus, which are states where muscle fibers are activated repeatedly without sufficient relaxation time between contractions, leading to an increase in muscle tension.

When the frequency of action potentials increases, the tension in the muscle unit continues to rise until it peaks at about three to four times greater than that of a single twitch during incomplete tetanus. If the stimuli are so frequent that relaxation phases are completely eliminated, a state of complete tetanus occurs where the contractions fuse, and muscle tension becomes maximal.