Nerve
Trigeminal nerve (CN V)
Three sensory divisions with motor output through V3
High-yield
V1 reaches the orbit through the superior orbital fissure, V2 passes through foramen rotundum and V3 through foramen ovale. Trigeminal skeletal motor fibers use V3; corneal-reflex input uses V1 and blinking output uses VII.
Overview
CN V connects the face and oral region with an extensive brainstem sensory system and supplies first-arch muscles. Large sensory and smaller motor roots attach to the lateral pons. Most sensory cell bodies occupy the trigeminal ganglion in Meckel's cave. The motor root bypasses that ganglion and joins the mandibular division near the skull base.
Learning this group? Read How to memorize the cranial nerves.
Reference facts
- Origin
- Most sensory neurons lie in the trigeminal ganglion; mesencephalic primary neurons serve jaw proprioception. Principal and spinal sensory nuclei process major sensory inputs, while the pontine motor nucleus supplies branchial motor output.
- Skull exit
- V1: superior orbital fissure. V2: foramen rotundum. V3: foramen ovale.
- Course
- Roots cross the cisternal region to Meckel's cave. V1 and V2 continue along the lateral cavernous-sinus wall before their skull-base openings; V3 enters the infratemporal fossa with the motor component.
- Motor
- V3 supplies masseter, temporalis, both pterygoids, mylohyoid, anterior digastric, tensor tympani and tensor veli palatini. Trigeminal branches also carry autonomic fibers originating elsewhere, including parasympathetic pathways associated with III, VII and IX.
- Sensory
- General sensation from most of the face, anterior scalp, eye surface, oral/nasal and sinus mucosa, teeth, TMJ and much cranial dura. Lingual V3 carries anterior-tongue general sensation; joined VII fibers carry taste. Cervical nerves cover some facial-edge territories.
Mnemonic
Three divisions, three openings: ophthalmic - fissure; maxillary - rotundum; mandibular - ovale.
Clinical correlation
Trigeminal neuralgia commonly affects V2 or V3, with brief attacks provoked by otherwise innocuous stimuli. Vascular root compression is one cause. Motor-root injury can weaken chewing and deviate the opening jaw toward the weak side. Corneal-reflex abnormalities require assessment of both sensory and facial-motor pathways.
Frequently asked questions
Where does the trigeminal nerve (CN V) arise?
Most sensory neurons lie in the trigeminal ganglion; mesencephalic primary neurons serve jaw proprioception. Principal and spinal sensory nuclei process major sensory inputs, while the pontine motor nucleus supplies branchial motor output.
What muscles does the trigeminal nerve (CN V) supply?
V3 supplies masseter, temporalis, both pterygoids, mylohyoid, anterior digastric, tensor tympani and tensor veli palatini. Trigeminal branches also carry autonomic fibers originating elsewhere, including parasympathetic pathways associated with III, VII and IX.
What is the sensory distribution of the trigeminal nerve (CN V)?
General sensation from most of the face, anterior scalp, eye surface, oral/nasal and sinus mucosa, teeth, TMJ and much cranial dura. Lingual V3 carries anterior-tongue general sensation; joined VII fibers carry taste. Cervical nerves cover some facial-edge territories.
Where does the trigeminal nerve (CN V) leave the skull?
V1: superior orbital fissure. V2: foramen rotundum. V3: foramen ovale.