How does a stretch reflex occur?

Answer 1

The receptor in the reflex arc of a stretch reflex are 'muscle spindles' which are spindle shaped receptors distributed throughout the belly of the muscle.

when the muscle gets stretched , muscle spindle is stimulated and it sends proprioceptive impulses via sensory afferent fibers in posterior root to anterior horn cells of the spinal cord. Motor impulses from anterior horn cells via motor efferent fibers in anterior root to muscle.

Answer 2

Reflex actions are actions you do without thinking, although the information does travel to the spinal cord, to protect yourself from immediate danger or harm. Example:coughing clears your windpipe, shivering keeps you warm. The pupils get smaller in bright light to protect the retina. Blinking helps to keep the eye clear and moist. This happens automatically even when there is no foreign body to get rid off.

Answer 3

A stretch reflex occurs in the muscles. When a muscle is stretched, the muscle spindles are activated and they send information to the brain that then responds telling the muscle to contract. This is a protective mechanism in the body that prevents muscles from being overstretched. When a muscle is rapidly stretched, elastic energy is stored in the muscle and the stretch reflex causes a quick contraction that can be used in sports/activities requiring a high burst of energy and a quick muscle contraction.

An example of a stretch reflex being used is a vertical jump. Before we jump, we squat down and bend at the knees. This stretches the quads, activating the muscle spindles. The quads then react by contracting which allows us to jump higher.