Solved Stretching a muscle spindle triggers a reflex called Biology Diagrams The monosynaptic stretch reflex, sometimes called the muscle stretch reflex or deep tendon reflex, is a reflex arc that facilitates direct communication between sensory and motor neurons innervating the muscle. This reflex initiates inside the muscle spindle, which detects both the magnitude and rate of muscle stretch. When the muscle is subjected to a stretch stimulus, sensory impulses are Muscle spindles are small sensory organs with an elongated shape, involved in proprioception. Image 2: Mammalian muscle spindle showing typical position in a muscle (left), neuronal connections in spinal cord (middle) and expanded schematic (right). The spindle is a stretch receptor with its own motor supply consisting of several intrafusal muscle fibres.
The stretch reflex is accomplished through several different structures. In the muscle, there are muscle spindles, whose intrafusal muscle fibers lie parallel to the muscle and sense changes in length and velocity. The afferent sensory neuron is the structure that carries the signal from the muscle to the spinal cord.
Golgi Tendon Organs and Muscle Spindles Explained Biology Diagrams
The stretch reflex is the contraction of a muscle that occurs in response to its stretch. It is not controlled by higher functioning centre i.e. the brain, and is a monosynaptic response that is transmitted to the spinal cord.Our body needs to be able to respond without our cortical input. In this article we will discuss the stretch reflex, the anatomy that underpins it, as well as the This process is called the stretch reflex. When a muscle spindle's associated muscle is rapidly stretched, the spindle can cause two things to happen: (1) it may signal its muscle to contract to prevent it from going too far, too quickly in the stretch; and (2) it can inhibit the opposing muscle (the antagonist to the muscle being stretched This monosynaptic reflex arc is variously referred to as the "stretch," "deep tendon," or "myotatic reflex," and it is the basis of the knee, ankle, jaw, biceps, or triceps responses tested in a routine neurological examination. The tap of the reflex hammer on the tendon stretches the muscle and therefore excites a volley of activity from the muscle spindles in the afferent axons.
The pathway starts when the muscle spindle is stretched (caused by the tap stimulus in the knee jerk reflex). The muscle spindles are responsible for detecting the length of the muscles fibres. When a stretch is detected it causes action potentials to be fired by Ia afferent fibres. These then synapse within the spinal cord with ฮฑ-motoneurones For this reason the stretch reflex is known as a spinal cord reflex and is completely involuntary. If the reflex was mediated by the brain precious time could be lost before the protective impulse to contract reached a stretched muscle, resulting inโฆ.a potentially far more serious injury. Muscle spindles are active with all exercise.
