Trigeminal nerve nuclei

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Brain: Trigeminal nerve nuclei

The cranial nerve nuclei schematically represented; dorsal view. Motor nuclei in red; sensory in blue. (Trigeminal nerve nuclei are at "V".)
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Latin	'
Gray's	subject #187 787
Part of
Components
Artery
Vein
BrainInfo/UW	ancil-1008020136
MeSH	A08.186.211.132.931

The sensory trigeminal nerve nucleus is the largest of the cranial nerve nuclei, and extends through the whole of the brainstem, midbrain to medulla.

The nucleus is divided into three parts, from rostral to caudal (top to bottom in humans), the mesencephalic nucleus, the chief sensory or pontine nucleus, and the spinal nucleus. There is also a distinct motor nucleus that is medial to the chief sensory nucleus.

The mesencephalic nucleus is involved with proprioception, that is, the feeling of position of the muscles. Unlike many nuclei within the CNS, the mesencephalic nucleus contains no synapses. Instead, neurons of this nucleus are pseudounipolar cells receiving proprioceptive information from the jaw, and sending projections to the motor trigeminal nucleus to mediate monosynaptic jaw reflexes. (BrainInfo at the University of Washington hier-550)
The chief sensory nucleus receives information about discriminative sensation and light touch as well as conscious proprioception of the jaw. (BrainInfo at the University of Washington hier-552)
The spinal trigeminal nucleus receives information about light touch, pain, and temperature from the ipsilateral face. The facial, glossopharyngeal, and vagus nerves also convey pain information from their areas to the spinal trigeminal nucleus. (BrainInfo at the University of Washington ancil-1015266456)

The spinal trigeminal nucleus is further subdivided into three parts, from rostral to caudal:

Pars Oralis
Pars Interpolaris
Pars Caudalis

There is also a distinct trigeminal motor nucleus that is medial to the chief sensory nucleus. This contains motor neurons that innervate muscles of the first branchial arch, namely the muscles of mastication, the tensor tympani, tensor veli palatini, mylohyoid, and anterior belly of the digastric. (BrainInfo at the University of Washington hier-551)