Question

Which of the following is true of a muscle spindle?

Answer 1

Answer:

This question lacks options, options are: A) are found within skeletal muscle. B) consist of specialized fibers called intrafusal fibers. C) are found in tendons. D) are the receptor for the stretch reflex. E) are innervated by gamma motor neurons.

The following options are true: A, B, D and E. The option C is false.

Explanation:

The muscle spindle are made up of contractile intrafusal muscle fibers only in their extremities (contractile and stretch-sensitive equatorial zone). Their function is to detect when the muscle changes its length, that is, when a stretch occurs, they are found in the skeletal muscle. These intrafusal muscle fibers are innervated by gamma motor fibers, causing a contraction. Therefore, the spindle is the part of the muscles that is located in the muscle belly parallel to the extrafusal fibers. The spindles present in the muscle fibers form what is known as the myotatic reflex, which helps regulate voluntary movement.