Trigeminal Nerve Branches
- “Standing Room Only”
- V1 -Superior orbital fissure, V2 -foramen Rotundum, V3 -foramen Ovale
Superior Orbital Fissure
- "Lazy French Tarts Lie Naked in Anticipation."
- (Lacrimal, Frontal, Trochlear, Lateral, Nasociliary, Internal, Abducens)
- I: Olfactory
- II: Optic
- III: Oculomotor
- IV: Trochlear
- V: Trigeminal
- V1: Ophthalmic
- V2: Maxillary
- V3: Mandibular
- VI: Abducens
- VII: Facial
- VIII: Vestibulocochlear
- IX: Glossopharyngeal
- X: Vagus
- XI: Accessory
- XII: Hypoglossal
- I: Olfactory; sense of smell; Located in olfactory foramina in the Cribriform plate of ethmoid
- II: Optic; Transmits visual information to the brain; Located in optic canal
- III: Oculomotor; Innervates levator palpebrae superioris, superior rectus, medial rectus, inferior rectus, and inferior oblique, which collectively perform most eye movements; Also innervates m. sphincter pupillae. Located in superior orbital fissure
- IV: Trochlear; Innervates the superior oblique muscle, which depresses, rotates laterally (around the optic axis), and intorts the eyeball; Located in superior orbital fissure
- V: Trigeminal; Receives sensation from the face and innervates the muscles of mastication; Located in superior orbital fissure (ophthalmic nerve - V1), foramen rotundum (maxillary nerve - V2), and foramen ovale (mandibular nerve - V3)
- V1: Ophthalmic branch; carries sensory information from the scalp and forehead, the upper eyelid, the conjunctiva and cornea of the eye, the nose (including the tip of the nose, except alae nasi), the nasal mucosa, the frontal sinuses, and parts of the meninges
- V2: Maxillary branch; carries sensory information from the lower eyelid and cheek, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and parts of the meninges
- V3: Mandibular branch; carries sensory information from the lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw, which is supplied by C2-C3), parts of the external ear, and parts of the meninges
- VI: Abducens; Innervates the lateral rectus, which abducts the eye; Located in superior orbital fissure
- VII: Facial; Provides motor innervation to the muscles of facial expression, posterior belly of the digastric muscle, and stapedius muscle, receives the special sense of taste from the anterior 2/3 of the tongue, and provides secretomotor innervation to the salivary glands (except parotid) and the lacrimal gland; Located and runs through internal acoustic canal to facial canal and exits at stylomastoid foramen
- VIII: Vestibulocochlear; Senses sound, rotation and gravity (essential for balance & movement). The vestibular branch carries impulses for equilibrium and the cochlear branch carries impulses for hearing.; Located in internal acoustic canal
- IX: Glossopharyngeal; Receives taste from the posterior 1/3 of the tongue, provides secretomotor innervation to the parotid gland, and provides motor innervation to the stylopharyngeus. Some sensation is also relayed to the brain from the palatine tonsils. Sensation is relayed to opposite thalamus and some hypothalamic nuclei. Located in jugular foramen
- X: Vagus; Supplies branchiomotor innervation to most laryngeal and all pharyngeal muscles (except the stylopharyngeus, which is innervated by the glossopharyngeal); provides parasympathetic fibers to nearly all thoracic and abdominal viscera down to the splenic flexure; and receives the special sense of taste from the epiglottis. A major function: controls muscles for voice and resonance and the soft palate. Symptoms of damage: dysphagia (swallowing problems), velopharyngeal insufficiency. Located in jugular foramen
- XI: Accessory; Controls sternocleidomastoid and trapezius muscles, overlaps with functions of the vagus. Examples of symptoms of damage: inability to shrug, weak head movement; Located in jugular foramen
- XII: Hypoglossal; Provides motor innervation to the muscles of the tongue (except for the palatoglossus, which is innervated by the vagus) and other glossal muscles. Important for swallowing (bolus formation) and speech articulation. Located in hypoglossal canal
- Cribriform plate: olfactory n. (CN I)
- Optic canal: optic n. (CN II) and ophthalmic a.
- Superior orbital fissure: oculomotor n. (CN III), trochlear n. (CN IV), ophthalmic n. (CN V1), abducens n. (CN VI), superior ophthalmic v.
- Foramen rotundum: maxillary n. (CN V2)
- Foramen ovale: mandibular n. (CN V3)
- Foramen spinosum: middle meningeal a.
- Foramen lacerum: nothing
- Internal acoustic meatus: facial n. (CN VII) and vestibulocochlear n. (CN VIII)
- Jugular foramen: glossopharyngeal n. (CN IX), vagus n. (CN X), accessory n. (CN XI), internal jugular v.
- Hypoglossal canal: hypoglossal n. (CN XII)
- Foramen magnum: accessory n. (enters skull), vertebral aa.