Final answer:
The number of myofibers receiving action potentials and the frequency of action potentials affect muscle force production.
Step-by-step explanation:
Neural Factors Affecting Muscle Force Production
The primary factors affecting muscle force production are the number of myofibers that receive action potentials from neurons and the frequency of action potentials.
When a small object, like a pencil, is picked up, only a few neurons in the biceps are signaled by the motor cortex, resulting in fewer myofibers responding. On the other hand, when a heavy object, like a piano, is lifted, all neurons in the biceps are signaled, and every myofiber participates, resulting in a near-maximum force.
Increasing the frequency of action potentials can further increase force production by flooding the tropomyosin with calcium.