The trigeminal ganglion (or Gasserian ganglion, or semilunar ganglion, or Gasser's ganglion) is a sensory ganglion of the trigeminal nerve (CN V) that occupies a cavity (Meckel's cave) in the dura mater, covering the trigeminal impression near the apex of the petrous part of the temporal bone.
Nerves of the orbit. Seen from above. (Semilunar ganglion visible near bottom.)
Distribution of the maxillary and mandibular nerves, and the submaxillary ganglion. (Semilunar ganglion visible in upper left.)
|Latin||ganglion trigeminale, ganglion semilunare (Gasseri)|
|Anatomical terms of neuroanatomy|
The motor root runs in front of and medial to the sensory root, and passes beneath the ganglion; it leaves the skull through the foramen ovale, and, immediately below this foramen, joins the mandibular nerve.
The greater superficial petrosal nerve lies also underneath the ganglion.
The ganglion receives, on its medial side, filaments from the carotid plexus of the sympathetic.
It gives off minute branches to the tentorium cerebelli, and to the dura mater in the middle fossa of the cranium.
The ophthalmic and maxillary consist exclusively of sensory fibers; the mandibular is joined outside the cranium by the motor root.
Herpes Labialis may follow from primary herpes infection/herpetic gingivostomatitis
The trigeminal ganglion is damaged, by infection or surgery, in Trigeminal trophic syndrome. Trigeminal trophic syndrome causes paresthesias and anesthesia, which may lead to erosions of the nasal ala.
In rodents, the trigeminal ganglion is important as it is the first part of the pathway from the whiskers to the brain. Cell bodies of the whisker primary afferents are found here. These afferents are mechanoreceptor cells that fire in response to whisker deflection.
There are around 26,000-43,000 cell bodies in rodent Trigeminal ganglion. It is possible that there are two distinct (or perhaps continuous) populations of cells having slowly and rapidly adapting responses to stimuli.