Stretch Reflex Explained | Muscle Spindle Activation

3-Second Blueprint (English)

1. Sensory intrafusal muscle spindles lie parallel to contractile extrafusal fibers and detect rapid muscle stretches.
2. A quick stretch sends an afferent signal to the spinal cord that activates the stretched agonist muscle to prevent injury.
3. Simultaneously, reciprocal inhibition suppresses the opposing antagonist muscle, as seen in the patellar tendon reflex.