Question

multiple choice question

during a crossed extension reflex, which nerve fibers cross to the contralateral side?

afferent
association
efferent

Explanation:

Analyze the reflex arc pathway

Using the Crossed Extensor Reflex knowledge point

In a crossed extensor reflex, a painful stimulus triggers a withdrawal reflex on the ipsilateral side, while simultaneously stimulating extension of the contralateral limb to maintain balance.

The sensory (afferent) fibers enter the ipsilateral dorsal horn of the spinal cord. They synapse with interneurons (also known as association neurons). To coordinate the contralateral response, the axons of these association (interneuron) fibers decussate (cross over) through the gray commissure to the contralateral side of the spinal cord, where they synapse with motor (efferent) neurons. Therefore, it is the association fibers that cross to the contralateral side.

Answer:

• Afferent
• Association (Correct answer)
• Efferent