The trigeminal ganglion (also known as: Gasserian ganglion, semilunar ganglion, or Gasser's ganglion) is the sensory ganglion of each trigeminal nerve (CN V). The trigeminal ganglion is located within the trigeminal cave (Meckel's cave), a cavity formed by dura mater.

Anatomy

The trigeminal ganglion contains cell bodies of the pseudo-unipolar sensory neurons of the trigeminal nerve which extend their axons both distally/peripherally into the three divisions of the trigeminal nerve on the one end, and proximally/centrally to the brainstem on the other end; the trigeminal root extends from the trigeminal ganglion to the ventrolateral aspect of the

pons The pons (from Latin , "bridge") is part of the brainstem that in humans and other mammals, lies inferior to the midbrain, superior to the medulla oblongata and anterior to the cerebellum. The pons is also called the pons Varolii ("bridge of ...

. The trigeminal ganglion is situated within the trigeminal cave (or Meckel's cave), a

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless Extracellular fluid#Transcellular fluid, transcellular body fluid found within the meninges, meningeal tissue that surrounds the vertebrate brain and spinal cord, and in the ventricular system, ven ...

-filled cavity formed by a double layer of dura mater overlying the trigeminal impression near the apex of the

petrous part of the temporal bone The petrous part of the temporal bone is pyramid-shaped and is wedged in at the base of the skull between the sphenoid and occipital bones. Directed medially, forward, and a little upward, it presents a base, an apex, three surfaces, and three ...

Structure

The trigeminal ganglion is somewhat crescent-shaped, with its convexity directed anterolaterally. From its convex border arise the ophthalmic nerve (V₁), maxillary nerve (V₂), and mandibular nerve (V₃). The ganglion receives, on its medial side, filaments from the carotid plexus of the sympathetic. It issues minute branches to the

tentorium cerebelli The cerebellar tentorium or tentorium cerebelli (Latin for "tent of the cerebellum") is one of four dural folds that separate the cranial cavity into four (incomplete) compartments. The cerebellar tentorium separates the cerebellum from the cere ...

, and the dura mater in the middle cranial fossa.

Relations

Medially to the trigeminal ganglion are the

internal carotid artery The internal carotid artery is an artery in the neck which supplies the anterior cerebral artery, anterior and middle cerebral artery, middle cerebral circulation. In human anatomy, the internal and external carotid artery, external carotid ari ...

, and the posterior part of the

cavernous sinus The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica. Structure The ...

. The motor root of the

trigeminal nerve In neuroanatomy, the trigeminal nerve (literal translation, lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for Sense, sensation in the face and motor functions ...

passes beneath the trigeminal ganglion to exit the skull through the foramen ovale. The greater petrosal nerve passes underneath the trigeminal ganglion to reach the foramen lacerum.

Clinical significance

Herpes virus dormancy

After recovery from a primary

herpes Herpes simplex, often known simply as herpes, is a viral infection caused by the herpes simplex virus. Herpes infections are categorized by the area of the body that is infected. The two major types of herpes are oral herpes and genital herp ...

infection, the

virus A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are ...

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

Lesions

If the trigeminal ganglion is damaged, by infection or surgery, it gives rise to the trigeminal trophic syndrome, which involves paresthesias and anesthesia, and may lead to erosions of the nasal ala.

Ablation in trigeminal neuralgia

The thermocoagulation or injection of

glycerol Glycerol () is a simple triol compound. It is a colorless, odorless, sweet-tasting, viscous liquid. The glycerol backbone is found in lipids known as glycerides. It is also widely used as a sweetener in the food industry and as a humectant in pha ...

into the trigeminal ganglion has been used in the treatment of

trigeminal neuralgia Trigeminal neuralgia (TN or TGN), also called Fothergill disease, tic douloureux, trifacial neuralgia, is a chronic pain, long-term pain disorder that affects the trigeminal nerve, the nerve responsible for sensation in the face and motor funct ...

Other animals

Rodents

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 Afferent nerve fibers are axons (nerve fibers) of sensory neurons that carry sensory information from sensory receptors to the central nervous system. Many afferent projections ''arrive'' at a particular brain region. In the peripheral nervou ...

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 The brainstem (or brain stem) is the posterior stalk-like part of the brain that connects the cerebrum with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is co ...

areas including principalis, spinal trigeminal nucleus, interpolaris, and caudalis.

Additional images

File:Gray193.png, Base of the skull. Upper surface. File:Gray777.png, Nerves of the orbit, and the ciliary ganglion. Side view. File:Gray783.png, The otic ganglion and its branches. File:Slide7nnn.JPG, Trigeminal ganglion File:Slide2ROM.JPG, Trigeminal ganglion. Deep dissection. Superior view.

References

External links

Diagram
at

University of Manitoba The University of Manitoba (U of M, UManitoba, or UM) is a public research university in Winnipeg, Manitoba, Canada. Founded in 1877, it is the first university of Western Canada. Both by total student enrolment and campus area, the University of ...

Diagram (as "Gasserian Ganglion")
at frca.co.uk * * * () {{Portal bar, Anatomy Sensory ganglia Cranial nerves