Trigeminal ganglion
Encyclopedia
The trigeminal ganglion (or Gasserian ganglion, or semilunar ganglion, or Gasser's ganglion) is a sensory ganglion
Ganglion
In anatomy, a ganglion is a biological tissue mass, most commonly a mass of nerve cell bodies. Cells found in a ganglion are called ganglion cells, though this term is also sometimes used to refer specifically to retinal ganglion cells....

 of the trigeminal nerve
Trigeminal nerve
The trigeminal nerve contains both sensory and motor fibres. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing. Sensory information from the face and body is processed by parallel pathways in the central nervous system...

(CN V) that occupies a cavity (Meckel's cave
Meckel's cave
The trigeminal cave is two layers of dura mater which encase the trigeminal ganglion near the apex of the petrous part of the temporal bone. It is bounded by the dura overlying four structures:...

) in the dura mater
Dura mater
The dura mater , or dura, is the outermost of the three layers of the meninges surrounding the brain and spinal cord. It is derived from Mesoderm. The other two meningeal layers are the pia mater and the arachnoid mater. The dura surrounds the brain and the spinal cord and is responsible for...

, covering the trigeminal impression near the apex of the petrous part of the temporal bone
Temporal bone
The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebrum.The temporal bone supports that part of the face known as the temple.-Parts:The temporal bone consists of four parts:* Squama temporalis...

.

Relations

It is somewhat crescentic in shape, with its convexity directed forward: Medially, it is in relation with the internal carotid artery
Internal carotid artery
In human anatomy, the internal carotid arteries are two major arteries, one on each side of the head and neck. They arise from the common carotid arteries where these bifurcate into the internal and external carotid artery, and they supply the brain....

 and the posterior part of the cavernous sinus
Cavernous sinus
The cavernous sinus , within the human head, is a large collection of thin-walled veins creating a cavity bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.-Contents:...

.

The motor root runs in front of and medial to the sensory root, and passes beneath the ganglion
Ganglion
In anatomy, a ganglion is a biological tissue mass, most commonly a mass of nerve cell bodies. Cells found in a ganglion are called ganglion cells, though this term is also sometimes used to refer specifically to retinal ganglion cells....

; it leaves the skull through the foramen ovale
Foramen ovale (skull)
At the base of the skull the foramen ovale is one of the larger of the several holes that transmit nerves through the skull. The foramen ovale is situated in the posterior part of the sphenoid bone, posterolateral to the foramen rotundum.-Contents:Several nerves, arteries and veins pass through...

, and, immediately below this foramen, joins the mandibular nerve
Mandibular nerve
The mandibular nerve is the largest of the three branches of the trigeminal nerve.-Roots:It is made up of two roots:* a large sensory root proceeding from the inferior angle of the trigeminal ganglion....

.

The greater superficial petrosal nerve lies also underneath the ganglion.

The ganglion receives, on its medial side, filaments from the carotid plexus
Carotid plexus
Carotid plexus can refer to:* Common carotid plexus* Internal carotid plexus* External carotid plexus...

 of the sympathetic.

It gives off minute branches to the tentorium cerebelli
Tentorium cerebelli
The tentorium cerebelli or cerebellar tentorium is an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes.-Anatomy:...

, and to the dura mater in the middle fossa of the cranium.

From its convex border, which is directed forward and lateralward, three large nerves proceed, viz., the ophthalmic
Ophthalmic nerve
The ophthalmic nerve is one of the three branches of the trigeminal nerve, the fifth cranial nerve. The ophthalmic nerve carries only sensory fibers.-Branches:*Nasociliary nerve**sensory root of ciliary ganglion**posterior ethmoidal nerve...

(V1), maxillary (V2), and mandibular
Mandibular nerve
The mandibular nerve is the largest of the three branches of the trigeminal nerve.-Roots:It is made up of two roots:* a large sensory root proceeding from the inferior angle of the trigeminal ganglion....

(V3).

The ophthalmic and maxillary consist exclusively of sensory fibers; the mandibular is joined outside the cranium by the motor root.

Clinical significance

After recovery from a primary herpes infection, the virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

 is not cleared from the body, but rather lies dormant in a non-replicating state within the trigeminal ganglion.

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.

Rodent

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.

It is found at the base of the skull and projects to trigeminal brain stem
Brain stem
In vertebrate anatomy the brainstem is the posterior part of the brain, adjoining and structurally continuous with the spinal cord. The brain stem provides the main motor and sensory innervation to the face and neck via the cranial nerves...

 areas including principalis, spinal trigeminal nucleus
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. The facial, glossopharyngeal, and vagus nerves also convey pain information from their areas to the spinal trigeminal nucleus.This nucleus...

, interpolaris, and caudalis.

External links

  • Diagram at University of Manitoba
    University of Manitoba
    The University of Manitoba , in Winnipeg, Manitoba, Canada, is the largest university in the province of Manitoba. It is Manitoba's most comprehensive and only research-intensive post-secondary educational institution. It was founded in 1877, making it Western Canada’s first university. It placed...

  • Diagram (as "Gasserian Ganglion") at frca.co.uk
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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