The ventral trigeminal tract, ventral trigeminothalamic tract, anterior trigeminal tract, or anterior trigeminothalamic tract, is a
tract composed of second order neuronal
axon
An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action ...
s. These fibers carry sensory information about discriminative and crude touch, conscious proprioception, pain, and temperature from the head, face, and oral cavity. The ventral trigeminal tract connects the two major components of the brainstem trigeminal complex – the
principal, or main sensory nucleus and the
spinal trigeminal nucleus
The spinal trigeminal nucleus is a nucleus in the medulla that receives information about deep/crude touch, pain, and temperature from the ipsilateral face. In addition to the trigeminal nerve (CN V), the facial (CN VII), glossopharyngeal (CN IX ...
, to the
ventral posteromedial nucleus
The ventral posteromedial nucleus (VPM) is a nucleus of the thalamus.
Inputs and outputs
The VPM contains synapses between second and third order neurons from the anterior (ventral) trigeminothalamic tract and posterior (dorsal) trigeminothalami ...
of the
thalamus
The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all direction ...
.
The ventral trigeminal tract is also called the anterior
trigeminal lemniscus
The trigeminal lemniscus, also called the trigeminothalamic tract, is composed of the ventral trigeminal tract, and the dorsal trigeminal tract – nerve tracts that convey tactile, pain, and temperature impulses from the skin of the face, the ...
.
Structure
The first order neurons (from the trigeminal ganglion) enter the pons and synapse in the
principal (chief sensory) nucleus or
spinal trigeminal nucleus
The spinal trigeminal nucleus is a nucleus in the medulla that receives information about deep/crude touch, pain, and temperature from the ipsilateral face. In addition to the trigeminal nerve (CN V), the facial (CN VII), glossopharyngeal (CN IX ...
. Axons of the second order neurons cross the midline and terminate in the
ventral posteromedial nucleus
The ventral posteromedial nucleus (VPM) is a nucleus of the thalamus.
Inputs and outputs
The VPM contains synapses between second and third order neurons from the anterior (ventral) trigeminothalamic tract and posterior (dorsal) trigeminothalami ...
of the contralateral
thalamus
The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all direction ...
(as opposed to the
ventral posterolateral nucleus
The ventral posterolateral nucleus (VPL) is a nucleus of the thalamus. Together with the ventral posteromedial nucleus (VPM), ventral posterior inferior nucleus (VPI) and ventromedial posterior nucleus (VMpo), it constitutes the ventral posteri ...
, as in the dorsal column medial lemniscus (DCML) system). The third order neuron in the thalamus then connects to the
sensory cortex The sensory cortex can refer informally to the primary somatosensory cortex, or it can be used as a term for the primary and secondary cortices of the different senses (two cortices each, on left and right hemisphere): the visual cortex on the ...
of the
postcentral gyrus
In neuroanatomy, the postcentral gyrus is a prominent gyrus in the lateral parietal lobe of the human brain. It is the location of the primary somatosensory cortex, the main sensory receptive area for the sense of touch. Like other sensory areas, ...
.
See also
*
Dorsal trigeminal tract
References
Sources
* Anthoney, T. R. (1993). Neuroanatomy and the neurologic exam: a thesaurus of synonyms, similar-sounding non-synonyms, and terms of variable meaning. CRC Press.
* Norton, N. S. (2016). ''Netter's head and neck anatomy for dentistry''. Elsevier Health Sciences.
External links
Trigeminothalamic tracts (Netter image)* https://www.dartmouth.edu/~rswenson/NeuroSci/chapter_7B.html
* http://www.medilexicon.com/medicaldictionary.php?t=48738
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Thalamic connections
Trigeminal nerve