The afferent limb of the jaw jerk (masseteric) reflex is mediated by cell bodies located in which nucleus?

• A Main sensory nucleus of the trigeminal nerve
• B Spinal nucleus of the trigeminal nerve
• C Motor nucleus of the trigeminal nerve
• D Mesencephalic nucleus of the trigeminal nerve ✓

Explanation

Proprioceptive fibers from the muscle spindles of masticatory muscles have their cell bodies in the mesencephalic nucleus of the trigeminal nerve, a unique nucleus containing primary sensory neurons within the CNS. These fibers synapse directly on the trigeminal motor nucleus, forming a monosynaptic stretch reflex whose afferent and efferent limbs both run in the mandibular nerve. The main sensory nucleus handles touch, and the spinal nucleus handles pain and temperature.

Reference: Snell's Clinical Neuroanatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.