Question

If the vertebrate of a reflex arc controlling leg movement is broken, what part of the nerve pathway may temporarily block the nerve impulse?

Answer 1

As Motor and sensory neurons are located in the leg and brain, respectively and the receptor is probably a part of either of those  it's not located in the vertebra. So we can say that the part of the nerve that may block the nerve impulse is the Interneuron. Hope this helps.

Answer 2

The broken vertebrae controlling the reflex arc of the leg movement can be temporarily blocked by the interneurons. The reflexes are controlled by the central nervous system, and interneurons are a part of it (the brain and the spinal cord). The pathway of the reflex arc of the leg movement from the sensory neurons and then back to the motor neurons will be blocked by the interneurons as the vertebrae is broken.

Hence, the answer is 'interneurons'.