[NEUROANATOMY] Macroscopic - Cranial Nerves

CRANIAL NERVES

I - Olfactory Nerve

Innervates Nasal Mucosa

Originates in the cerebrum, exits through the Cribiform plate

II - Optic Nerve

Innervates Retina

Originates in the cerebrum, exits through the optic canal

III - Oculomotor Nerve

Innervates majority of extraocular muscles (levator palpebrae superioris, superior rectus, inferior rectus, medial rectus, and inferior oblique)

Originates in the midbrain-pontine junction

IV - Trochlear

Innervates the superior oblique muscle

Originates in the midbrain, exits through the superior orbital fissure

V - Trigeminal

Innervates scalp, face, orbit, paranasal sinuses, anterior two-thirds of the tongue

Innervates muscles of mastication, mylohyoid, anterior belly of digastric, tensor tympani muscles

Originates in the pons, exits through the (1) Opthalmic-Superior orbital fissure, (2) Foramen (Maxillary) and (3) Foramen ovale (Mandibular)

Trigeminal (Opthalmic)

Sensory to scalp, forehead and nose

Trigeminal (Maxillary)

Sensory to cheeks, lower eyelid, nasal mucosa, upper lip, upper teeth and palate

Trigeminal (Mandibular)

Sensory to anterior 2/3 tongue, skin over mandible and lower teeth and motor to muscles of mastication

VI - Abducens Nerve

Innervates the lateral rectus muscle

Originates in the Pontine-medullary junction, exits through Superior orbital fissure

VII - Facial Nerve

Innervates middle ear, nasal cavity, soft palate; anterior two-thirds of the tongue; external auditory meatus

Innervates lacrimal, submandibular, sublingual, basal, palatine glands; muscles of facial expression

Originates in the Pontine-medullary junction, exits through Internal acoustic meatus to the Stylomastoid foramen

VIII - Vestibulocochlear Nerve

Innervates the spiral organ (of Corti), macula of utricle, macula of saccule, ampullae of the semicircular canals

Originates in the Pontine-medullary junction, exits through the internal acoustic meatus

IX - Glossopharyngeal Nerve

Innervates posterior one-third of the tongue; middle ear, pharynx, epiglottis, carotid body, carotid sinus; posterior one-third of the tongue, soft palate

Innervates stylopharyngeus and pharyngeal constrictors; parotid gland

Originates in the medulla oblongata, exits through the Jugular foramen

X - Vagus Nerve

Innervates epiglottis; thoracic and abdominal viscera, carotid body; external acoustic meatus, retroauricular skin, posterior part of meninges

Innervates thoracic and abdominal viscera; laryngeal and pharyngeal muscles

Originates in the medulla oblongata, exits through the Jugular foramen

XI - Spinal Accessory Nerve

Innervates laryngeal muscles, sternocleidomastoid, trapezius

Originates in the medulla oblongata, exits through the Jugular foramen

XII - Hypoglossal Nerve

Innervates intrinsic tongue muscles, extrinsic tongue muscles (except for the palatoglossus)

Originates in the medulla oblongata, exits through the hypoglossal canal

Sensory Cranial Nerves

Olfactory

Optic

Vestibulocochlear

Motor Cranial Nerves

Oculomotor

Trochlear

Abducens

Spinal Accessory

Hypoglossal

Sensory and Motor Cranial Nerves

Trigeminal

Facial

Glossopharyngeal

Vagus

Specific Function of CN I

Smell

Specific Function of CN II

Vision

Specific Function of CN III

Movement of the eye muscles, constriction of the pupil, focusing the eyes, and the position of the upper eyelid

Specific Function of CN IV

Control eye movement (intorsion, downward gaze); motor to one extrinsic eye muscle

Specific Function of CN V

Sensory to face and teeth; Motor to mastication (chewing)

Specific Function of CN VI

Eye movement (abduction, lateral movements); Motor to one extrinsic eye muscle

Specific Function of CN VII

Sensory to Taste

Motor to Muscles of facial expression

Parasympathetic to salivary and tear glands

Specific Function of VIII

Cochlear part enables hearing

Vestibular part mediates balance and motion

Specific Function of CN IX

Enables speech, swallowing, salivation, and taste sensation; 

Visceral and general sensation in the oral cavity

Specific Function of CN X

Parasympathetic supply to visceral organs; 

Controls gland secretion, peristalsis,phonation, taste, visceral and general sensation of the head, thorax, and abdomen

Specific Function of CN XI

Motor to neck and upper back muscles

Specific Function of CN XII

Movement of Tongue Muscles