Trigeminal lemniscus

[TA] collective term denoting the fibers ascending from the sensory nuclei of the trigeminus; one such fiber system originates from the spinal trigeminal nucleus and from the principal sensory nucleus, decussates, and ascends as the anterior trigeminothalamic tract [TA] (ventral trigeminothalamic tract [TAalt]) in close association with the medial lemniscus with which it enters the ventrobasal complex to terminate in the ventral posteromedial nucleus; a second, uncrossed, fiber group originates from the principal sensory nucleus that follows an ascending course through central parts of the mesencephalic tegmentum as the posterior trigeminothalamic tract [TA] (dorsal trigeminothalamic tract [TAalt]) also to terminate in the ventral posteromedial nucleus. The trigeminal lemniscus conveys tactile, pain, and temperature impulses from the skin of the face, the mucous membranes of the nasal and oral cavities, and the eye, as well as proprioceptive information from the facial and masticatory muscles. SYN: lemniscus trigeminalis [TA].