Secretomotor fibres carried on trigeminal branches
Postganglionic · M3 V2 → V1 lacrimal V3 lingual V3 auriculotemporal
Postganglionic parasympathetic fibres from the three secretomotor head ganglia reach their glands by hitch-hiking on branches of the trigeminal nerve: zygomatic (V2) then lacrimal (V1) to the lacrimal gland, lingual (V3) to the submandibular and sublingual glands, and auriculotemporal (V3) to the parotid.
Traced from the start
- Parasympathetic (craniosacral) outflow
- Superior and inferior salivatory nuclei (CN VII and IX)
- Pterygopalatine (sphenopalatine) ganglionSubmandibular ganglionOtic ganglion
- Secretomotor fibres carried on trigeminal branches
Detail
- Pterygopalatine → lacrimal gland
- Zygomatic nerve (V2) → zygomaticotemporal branch → communicating branch → lacrimal nerve (V1) → gland; nasal and palatine glands via nasopalatine and palatine nerves
- Submandibular → glands
- Direct short branches to the submandibular gland; via the lingual nerve to the sublingual gland
- Otic → parotid
- Auriculotemporal nerve (V3), which also carries sensation from the temple and auricle
When it goes wrong
Trigeminal (V3) nerve block or lingual nerve injury during third molar extraction
Reduced salivation on that side alongside tongue numbness, because the postganglionic fibres share the lingual nerve
Parotid surgery with regeneration of auriculotemporal parasympathetic fibres into the skin
Frey syndrome: gustatory sweating over the cheek — treated with topical glycopyrrolate or botulinum toxin, both acting on the cholinergic sweat gland
Practise this structure
1 question in the bank tagged Trigeminal Nerve.