Question

As Abe continued his fitness regimen, he started to think more about his muscle anatomy. He wondered how he was able to adjust the force generated by his muscles when he lifted different weights. His anatomy instructor explained motor units to him. Which of the following best explains how motor units are involved in controlling force exerted by muscle?
A. A single motor neuron innervates a specific set of muscle tibers within each muscle. When more force is needed, more motor units are activated, which states mere matice fbers to contract
B. A motor unit in composed of all the muscle fibers within a singie tascich Addition fascicles will be activated when more force is needed
C. Each skeletal muscle fer is innervated by a single motor neuron, so there are as many motor neurons as fibers within a single musch When more force is needed addition motor neurons will be activated, and their individual fibers will contract
D. Each muscle has one motor neuron that can selectively activate as many foers as are needed when trying to in heaver objects a single motor neuror will just some more Ebers to contract Submit Putn Muscle shorteninn

Answer 1

Answer:

d). A single motor neuron innervates a specific set of muscle fibers within each muscle. When more force is needed, more motor units are activated, which stimulates more muscle fibers to contract.

Explanation:

The last statement most appropriately elaborates the role of motor units in directing the force applied by the muscles. It correctly states that 'a one motor neuron excites a particular range of muscle fibers in every muscle. In the situation of extra force required, there is an activation of extra motor units that assists in arousing the extra muscle fibers to shrink.' This contraction of muscles fibers in the concept 'motor units' assists the body to handle the distinct forces exerted by the body muscles when various weights are lifted. Thus, option d is the correct answer.