Lingual nerve

Recommended video: Mandibular nerve [19:26]

Course and branches of the mandibular branch of the trigeminal nerve.

The lingual nerve arises as one of the major branches of the posterior division of the mandibular nerve (CN V3), deep to the lateral pterygoid muscle in the infratemporal fossa. 

From its origin point, the lingual nerve extends inferiorly and is joined by the chorda tympani (branch of facial nerve (CN VII)). It courses between the lateral pterygoid and tensor veli palatini muscles and extends superficial to the medial pterygoid muscle. At the posterior margin of the mylohyloid line, the lingual nerve travels along the internal surface of the mandible and is located deep to the mylohyoid muscle within the floor of the mouth. From here the lingual nerve extends anteriorly passing from lateral to medial under the submandibular gland to enter the lateral margin of the mid-tongue. 

The lingual nerve is entirely sensory from its origin point but receives secretomotor parasympathetic fibers and special visceral sensory fibers for taste from the chorda tympani (branch of facial nerve (CN VII)). 

The lingual nerve has several branches, most of which are indistinct fibers rather than identifiable nerves. Main branches of the lingual nerve include the sublingual nerve, lingual branches, gingival branches and branches to the submandibular and sublingual ganglia (autonomic fibers synapse in ganglia). 

Through these branches the lingual nerve provides sensory innervation to the mucosa of the anterior 2/3 of the tongue, floor of the mouth and the lingual gingiva; secretomotor parasympathetic fibres to the submandibular, sublingual and minor salivary glands and special visceral sensory fibers for taste to the anterior 2/3 of the tongue.