Anatomy and Structure - Trigeminal ganglion contains cell bodies of sensory neurons of trigeminal nerve - Axons extend into three divisions of trigeminal nerve and brainstem - Situated within trigeminal cave (Meckels cave) - Trigeminal root extends from ganglion to pons - Ganglion receives filaments from carotid plexus and issues branches to tentorium cerebelli and dura mater - Trigeminal ganglion is crescent-shaped with convex border - Ophthalmic, maxillary, and mandibular nerves arise from convex border - Ganglion has medial relation to internal carotid artery and cavernous sinus - Motor root of trigeminal nerve passes beneath ganglion - Greater petrosal nerve passes underneath ganglion to reach foramen lacerum

Relations - Internal carotid artery and posterior part of cavernous sinus are medial to ganglion - Motor root of trigeminal nerve passes beneath ganglion - Greater petrosal nerve passes underneath ganglion to reach foramen lacerum

Clinical significance - Herpes virus lies dormant in trigeminal ganglion after primary infection - Damage to ganglion can cause trigeminal trophic syndrome with paresthesias and anaesthesia - Ablation of trigeminal ganglion can be used in the treatment of trigeminal neuralgia

Other animals - Trigeminal ganglion is important in rodents for pathway from whiskers to brain - Cell bodies of whisker primary afferents are found in ganglion - Ganglion projects to trigeminal brain stem areas in rodents - Rodent trigeminal ganglion has around 26,000-43,000 cell bodies - Two distinct populations of cells with different responses to stimuli may exist in ganglion

Noteworthy details - Ganglion receives filaments from carotid plexus and issues branches to tentorium cerebelli and dura mater - Ganglion has medial relation to internal carotid artery and cavernous sinus - Motor root of trigeminal nerve passes beneath ganglion - Greater petrosal nerve passes underneath ganglion to reach foramen lacerum