Respuesta :
The sensory endings of intrafusal muscle fibers stretch when the muscle lengthens and relax when it shortens.
Intrafusal muscle fibers are skeletal muscle fibres that serve as specialized sensory organs (proprioceptors). They detect the amount and rate of change in length of a muscle. They constitute the muscle spindle, and are innervated by both sensory (afferent) and motor (efferent) fibers.
There are two types of intrafusal muscle fibers:
- Nuclear bag fibers
- Nuclear chain fibers
They bear two types of sensory ending, known as annulospiral and flower-spray endings. Both ends of these fibers contract, but the central region only stretches and does not contract.
Intrafusal muscle fibers are walled off from the rest of the muscle by an outer connective tissue sheath consisting of flattened fibroblasts and collagen. This sheath has a spindle or "fusiform" shape, hence the name "intrafusal".
Function :
Intrafusal muscle fibers detect the amount and rate of change in muscle length. It is by the sensory information from gamma motor neurons and beta motor neurons that an individual is able to judge the position of their muscles.
Learn more about Intrafusal muscle fibers here : https://brainly.com/question/12993297
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