Tapping the patellar tendon with a reflex hammer produces a brief contraction of the knee extensors. What is the cause of the muscle contraction?
Ans. C. Muscle spindle activationMuscle spindles monitor muscle length. If the muscle is suddenly stretched, the spindle produces action potentials that activate homonymous motor neurons to contract the stretched muscle and resist the length change.
Elastic rebound of muscle connective tissue
Golgi tendon organ response
Muscle spindle activation
Muscle spindle unloading
Nervous System