spinal nucleus of trigeminal nerve

spi·nal nu·cle·us of tri·gem·i·nal nerve

the long sensory nucleus extending from the caudal border of the pontine sensory nucleus of the trigeminus down through the lateral region of the rhombencephalon into the upper three segments of the spinal cord's dorsal horn; it receives the fibers of the sensory root of the trigeminal nerve that descend along its lateral border as the spinal tract of trigeminal nerve [TA]. Small numbers of fibers to the nucleus originate on cranial nerves VII, IX, and X. This nucleus is divided into a pars caudalis [TA] (caudal part [TA]), a pars interpolaris [TA] (interpolar part [TA]), and a subnucleus oralis [TA] (oral subnucleus [TA]). The pars caudalis is further organized into a subnucleus zonalis [TA] (zonal subnucleus [TA]), a subnucleus gelatinosus [TA] (gelatinosus subnucleus [TA]), and a subnucleus magnocellularis [TA] (magnocellular subnucleus [TA]).