Answer:
The correct answer is B. Tapping the patellar tendon will usually result in a spinal reflex.
Explanation:
The patellar reflex is the involuntary contraction of the quadriceps femoris muscle by flexion of the patellar tendon. It is a reflex of spinal or stretching type. It was discovered, studied and first reported in 1875 by William Erb.
By striking the patellar tendon, the leg is extended as alpha motor neurons direct a nerve impulse to the quadriceps femoris muscle. The femoral nerve, responsible for such reflex, extends throughout the thigh and its synapses are found in the lumbar spinal nerve 2 to 4 of the spinal cord. Therefore, this movement is involuntary and responds to a need for automatic regulation of body muscles.
