Question

Motor units are important in the way a muscle works. What are they? Do all muscles have the same number of motor units? How would the number of motor units affect a muscle action?

Answer 1

Answer and Explanation:

• Motor units are made up of motor neurons and the fibers of the skeletal muscle connected by the terminals of the axon of the respective motor neurons.

• Motor units often work in groups in order regularly cooperate to organize the compression of a solitary muscle. The motor units as a whole inside a muscle are viewed as a motor pool.
• The muscle fibers in the motor unit are all same. On activation of a motor unit, contraction occurs in all of its fiber.
• In vertebrates, the muscle contraction force is governed by the number of motor units in active state.

• The activation of greater number of motor neurons will lead to the activation of a greater number of muscle fibers and hence a stronger contraction of the muscle.