CRANIAL NERVES By:Rabia ZulfiqarBy:Rabia Zulfiqar

Above the superior nasal concha

Nasal epithelium present

Olfactory cells present on epithelium

OLFACTORY NERVE :I (sensory nerve)Central processes come out from the olfactory cells

central process form olfactory nerve

olfactory nerve enter into the olfactory bulb

which lie in the cribriform plate of ethmoid bone

mitral & tuft cells in olfactory bulb gives off fibers that form olfactory tract

medial tracts decussate go into right & left.lateral tract ant.into perforated plate and finally into visual cortex area (periamygdaloid prepiriform fossa)

OPTIC NERVE : II (sensory )

In Eye , granular layer of ratina gives off Axons

Optic nerve enter into the optic chiasma

Axons converge into optic disc and form optic nerve

All fibers end into Lateral geniculate body, pretactal nucleus and superior colliculus

Medial tacts decusate and go into opposite side but lateral tacts run contralaterally

in chiasma , optic tracts form . (medial & lateral tracts)

Lateral geniculate body converge fibers as an optic radiation.

Ends into the primary visual cortex area and then into 2ndry visual Cortex area

Occulomotor N (III) : motor nervebegins from superior colliculus

Pass b/w 2 arteries (pos.cerebral & sup.cerebellar

Lateral wall

Cavernous Sinus

Divide

Sup. & Inf.

divisions

Superior orbital fissure

sup. division --> Superior Rectus & levator palpebral Superiorus

Inf.division --> inf.rectus , inf. oblique , Medial rectus

Begins from inferior colliculus

Lateral wallCavernous S

Superior orbital fissure

Pass b/w 2 arteries (pos.cerebral & sup.cerebellar

supply to Lateral rectus muscle of eye

Suply to the Superior oblique muscle of eye

Abducent Nerve (VI)Groove B/w pons and medulla

withinCavernous Sinus closely related to internal carotid artery

Superior orbital fissure

Trochlear Nerve (IV)

lll , lV, Vl NervesOLFACTORY NERVE :I

OPTIC NERVE : II

TRIGEMINAL NERVE (V) : Posterior.cranial fossa

Middle cranial fossa

Lies at petrous temporal bone in Meckel's cave

Where sensory components form trigeminal ganglion . V ganglion gives off 3 branches

Begin from Anterolateral part of pons

Trigeminal ganglion

Ophthalmic Nerve

Maxillary nerve

Mandibular Nerve

Ophthalmic Division :Ophthalmic Nerve

Frontal

Nasociliary

Lacrimal

Supratrochlear

supraorbital

post.ethmoidal

Long ciliary

Nerve to ciliary

ganglion

infratrochlear

Ant.ethmoidal

sphenoidal,post.ethmoidal air sinus

sensory to eyeball

frontal air sinus,

upper eyelid,,forehead,scalp till vortex

upper eyelid, conjuctiva,lower part of forehead.

middle/ant.ethmoidal air sinus,medial/lateral internal nasal

lateral part of uppereyelid , lacrimal gland.

Both eyelids,side of nose,lacrimal sac

trigeminal ganglion

leaves middle cranial fossa by passing through foramen rotendum gives meningeal branches

Infraorbital nerve

MAXILLARY NERVE :

through infraorbital foramina emerge on face

cavernous sinus

pterygopalatine fossa

zygomatic

pos.sup.alveolar

zygomaticotempor

al

zygomaticofacial

Ganglionic branches

in infraorbital canal

middle.sup.alveolar

Ant.sup. Alveolar

on face

Nasal

labialpalpebral

Orbital branch

Palatine branch

Nasal branch

Pharyngeal branch

MANDIBULAR NERVE Trigeminal ganglion

Middle cranial fossa

sensory root present lateral to v ganglion

Leave cranial cavity through foramen ovale

through 2 roots

Sensory Motor root

lie deep to trigeminal ganglion

pass through foramen ovale

just below the foramen ovale. sensory and motor root join to form main trunk.it lie into ifratemporal fossa

Ant.division

Messeteric

Buccal nerve

Deep to the temporal nerve

nerve to lateral pterygoid

Post.division

Auriculartemporal

Lingual

Inf.alveolar nerve

mylohyoid and mental branch

FACIAL NERVE

Derived from 2nd brachial archNuclei (4)

Brachimotor lacrimatory Tractus solitarissup.salivatory

VII nerve attached to brainstemby 2 roots

VII nerve attached to brainstemby 2 roots

Sensory (nervous intermedius)

Sensory (nervous intermedius)

MotorMotor

2 roots attached to lateral part of lower border of pons.run lateral /4wd to reach interacusticmeatus

In meatus,motor root lie in a groove

lie in a petrous temporal bone

fundus of meatus,two roots fuse to form single trunk

Directed laterally, above the vestibule

At the junction of 1st & 2nd part.lie over anterosuperior part of pro,omtory

run backward,present above promontory

Within canal course of nerve

gives 3 parts 2 bends

1st bend 2nd bend1st part 2nd part 3rd part

Lie b/w promontory and aditus of mastoid antrum

vertically downward, behind promontory

Nerve leave the skull through stylomastoid foramina.In Extracranial Course,7th nerve crosses the lateral side of styloid process.it enter into the parotid gland.Run 4wd through glan and crosses the retromandibular vein and external carotid artery.divides into 5 terminal branches. Branches

Within canal

graeter petrosal nerve

Nerve to stapedius

chorda tympani

At exit from foramina Parotid gland

Zygomatic

BuccalMarginal Mandibular

Post.Auricular

Digastric

Stylohyoid

Cervical Temporal

Vestibulocochlear VIII (sensory)Eight cranial nerve. it is a sensory nerve. It contain two part Vestibular Part

(For static & kinetic balance)

Cochlear Part (For Hearing)

Leaving the skull by Passing through jugular foramina

Originate b/w olive &inf.cerebellar peduncle

Glossopharyngeal Nerve (IX)MixedPost.cranial fossa ------>

middle cranial fossa

motor root supply to stylopharyngeus & sensory root supply to post.1/3 of tongue

Nuclei :Nucleus Ambigus (Brachiomotor)Inferior salivatory (parasympathetic)Tractus solitarus (Gustatory)

Branches & Distribution

Tympanic branch (middle ear,auditory tube & mastoidantrum)Carotid branch (carotid sinus & carotid body)Pharyngeal Branch (mucous membrane of pharynx)Muscular branch(stylopharyngeus muscle)Tonsillar (tonsill & soft palate )Lingual branch (carry taste & gen.sensation fro post. 1/3 of tongue)

Vagus nerve (X): Mixed nerve : Nucleus l-Nucleus Ambigus ll-Dorsal nucleus of vagus lll-Nucleus of tractus solitarius lv-Nucleus of spinal tract of trigeminal.

originate b/w olive & inf.cerebellar peduncle

Nerve pass laterally through pos.cranial fossa

Leaves the skull by passing through jugular foramen b/w sigmoid & inf.petrosal sinus

In foramen ,it is joined by cranial root of accessory nerve

nerve enter into carotid sheath

it passes through mediastenum of thorax , passing behind the roots of lung & enter the abdomen through esophageal opening in diaphram

Vagus nerve has 2 ganglia

Sup.ganglia (gives 2

branches)

Inf.ganglia (gives off branches)

I-Auricular branch (tumpanic membrane,concha,root of auricle)

II-Meningeal branch (dura of pos.cranial fossa)

l-Pharyngeal Branch : (soft palate except tensor veli palatini )

ll-carotid Branch:(carotid sinus & carotid body)

lll-sup.laryngeal : (cricothyroid muscle,mucous membrane of larynx)

lv- Right recurrent laryngeal

v-cardiac

Accessory Nerve (XI) (Motor )Spinal root Arise from upper 5 segment of spinal cord

Cranial root Arise from lower part of nucleus ambigus

Two roots enter into the jugular foramen

in foramen,cranial root unite for a short distence with spinal root

Again cranial root separate from spinal root as it passes out of foramen

Spinal root supply to the trapezius and sternocleidomasoid muscle & cranial root supply to the muscle of soft palate , pharynx & larynx.

HYPOGLOSSAL NERVE (XIl)It emerges from ant. surface of medulla b/w olive & pyramid . It crosses the pos.cranial fossa and leaves the skull through hypoglossal canal. nerve then pass downward and forward in the neck and crosses the ext. & internal carotid arteries to reach the tongue.

Supply: It is supply to the all intrinsic and extrinsic muscle of tongue except palatoglossus, it is supplied by vago acessory complex.