Question

A motor unit is best described as:
A) all the nerve fibers and muscle fibers in a single muscle bundle.
B) one muscle fiber and its single nerve fiber.
C) a single motor neuron and all the muscle fibers that it innervates.
D) the neuron that provides the CNS with information on the state of contraction of the muscle.

Answer 1

Hint:
These units are responsible for every movement and control of the skeletal system. Like voluntary actions like walking, and weightlifting and also involuntary roles like breathing. As we lift the weight, our body adapts to motor needs.

Complete step by step answer:
It is the functional segment of skeletal muscles. It has two main parts: A different single motor neuron (it is a neuron that carries signals away from the central nervous system) and the muscle fibers.
Additional information Myosin is an actin filament-based motor protein. The form of myosin is found in the muscle and was first identified as myosin 2. Each molecule is an oligomer composed of one pair of identical heavy chains and two pairs of non-identical light chains. A major role of the rodlike tail of myosin 2 is to allow the molecules to polymerize into bipolar filaments. These tail interactions result in the formation of large bipolar thick filaments that have several myosin heads, oriented in opposite directions at the two ends of the thick filament.

Option ‘C’ is correct

Note:
The motor unit consists of the horn cell, peripheral nerve, and multiple terminal axons on the anterior side. Each of them innervates many individual muscle fibers. A skeletal fascicle has 20 to 60 fibers which are surrounded by connective tissue.