Lanka Ranaweera

Dept. of Anatomy

CRANIAL NERVES

Objectives

• Describe the anatomy of V nerve

• Describe the sensory distribution of face

• Name the muscles of mastication

• Describe the features of lesions of V nerve

• Describe the anatomy of VI nerve

• Describe the anatomy & functions of VII nerve

• Describe the features of lesions of VII nerve

NERVOUS SYSTEM

Structurally Functionally

central N.S.

peripheral N.S.

somatic N.S.

autonomic N.S.

spinal nerves (31)

cranial nerves (12)

symp. para.spinal cord brain

I Olfactory nerveII Optic nerve III Occulomotor nerveIV Trochlear nerveV Trigeminal nerveVI Abducent nerveVII Facial nerve

VIII Vestibulocochler nerveIX Glossopharyngeal nerveX Vagus nerveXI Accessary nerveXII Hypoglossal nerve

Cranial nerves

Trigeminal Nerve (V)

• Largest cranial nerve

• 3 divisions : opthalmic / maxillary / mandibular

• Functional components : Sensory & motor

• Function : sensory - grater part of the head

motor - several mm (C mastication mm)

• Opening in skull : superior orbital fissure (opthalmic)

foramen rotundum ( maxillary)

foramen ovale (mandibular )

_

Trigeminal ganglion

Trigeminal Nerve

Trigeminal nerve nuclei in the brain stem

Motor nucleus

Main sensorynucleus

Trigeminal ganglion

Mescencephalic nucleus

Spinal nucleus

Opthalmic

Maxillary

Mandibular

pons

Medulla oblongata

Spinal cord

thalamus

midbrain

Trigeminal lemniscus

Cerebral cortex Motor nucleus of V nerve

Main sensorynucleus of V nerve

Trigeminal ganglion

Trigeminal nerve

Mescencephalic nucleus

Trigeminal nerve nuclei & its

central connections

pons

Midbrain

II & optic tractIII

IV

VVI

VIIVIII

IX

XI

XIIX

Olfactory bulb Olfactory tract

Infundibulum & mamilary body

Base of the brain

Pathway of the Trigeminal nerve Trigeminal nerve

leaves anterior of pons(small motor root & larger sensory root)

forward out of posterior cranial fossa

middle cranial fossa

rest on petrous part of temporal bone

Sensory root forms trigeminal ganglion

Ophthalmic nerve maxillary nerve mandibular nerve

(sensory) (sensory) (sensory + motor)

superior orbital foramen rotundum foramen ovale

fissure

Ophthalmic division (V1)

frontal nerve lacrimal nerve nasociliary nerve

Supratrochlear supraorbital

scalp up to vertex upper eye lid ciliary ganglion

upper eyelid lacrimal gland eyeball

frontal air sinus conjunctiva cornea

conjunctiva

dorsum of nose

Supratrochlear nerve

Supraorbital nerve

Lacrimal nerve

Zygomatic nerve

Infratrochlear nerve

Ant. ethmoidal nerve

frontal nerve

Pos. ethmoidal nerve

opticl nerve

nasociliary nerve

Opthalmic nerve

Short ciliary nerve

Long ciliary nerve

Ciliary ganglion

Opthalmic division of trigeminal nerve

Maxillary division (V2)

Zygomatic nerve Infraorbital nerve Pteregopalatine ganglion branches

Foramen rotundum

Pteregopalatine fossa

Infra orbital fissure

Skin of templelower eye lidupper lipskin of cheek

teeth-upper jaw

maxillary sinus

mucous mem. of palate nasopharynx uvula, tonsils Nasal septum

Pterigopalatine ganglion

Zygomatic nerve

Infraorbital nerve

Ant. sup. alveolar nerve

Post. sup. alveolar nerve

Lacrimal nerve

Maxillary division

Maxillary division of trigeminal nerve

Mandibular division (V3)

Anterior trunk posterior trunk

Buccal nerve motor branch auricular- lingual inferior (sensory) -temporal n. nerve alveolar n.

foramen ovale

Infratemporal fossa

Skin of cheek masseter skin of temple floor of mouth ???

Mucose mem.- temporalis skin of auricle ant.2/3 of tongue*

-of cheek Lateral pterygoid sublingual gland** submandibular gland** * associated c chorda tympani from VII nerve ** via submandibular ganglion

Nervus spinosus

Nerve to Medial--pterygoid

Otic ganglion

Tensor

tympani

Tensor

palati

(sensory)

+

_

Inferior alveolar nerve mental nerve

nerve to mylohyoid

Teeth of lower jaw mylohyoid mm skin of chin

anterior belly of digastric lower lip

+ +

Mandibular canal

Auriculotemporalnerve

Foramen ovale

Mandibular division of trigeminal nerve

Nerve to temporalis

Nerve to masseter

Nerve to pterygoid

Mental nerve

Inferior alveolar nerve

Lingual nerve

Parotid branch

Nerve to mylohyoid

Buccal nerve

Sensory distribution of face & scalp by trigeminal nerve

Features of lesions trigeminal nerve

• Wasting of muscles of mastication

• Loss of sensory modalities

Abducent Nerve (VI)

• Functional component : motor

• Function : turns eyeball laterally

• One motor nucleus –pons

• Opening in skull : superior orbital fissure

Abducent Nerve

Cerebral cortex

Nucleus of VI nerve

Abducent nerve

Medial longitudinal fasciculus

Tectobulbar fibers from sup. colliculus

Abducent nerve nucleus & its central connectionspons

Midbrain

II & optic tractIII

IV

VVI

VIIVIII

IX

XI

XIIX

Olfactory bulb Olfactory tract

Infundibulum & mamilary body

Base of the brain

Pathway of the abducent nerve

Abducent nerve anteriorly through pons

through cavernous sinus groove between lower border of pons & medulla oblongata

Lateral relation : 3/4/5/ cranial nerves Medial relation : internal carotid artery

Superior orbital fissure orbit lateral rectus muscle

pituitary

Internal carotid artery

Sphenoid sinus

V2

VI

V1

IVIII

Cavernous sinus in coronal section

Mid brain

pons

Abducent nerve

Medulla oblongata

Distribution of the abducent nerve

Lateral rectus

Facial Nerve(VII)

• Functional component: motor

sensory

secretomotor/parasympathetic

• 3 nuclei in pons : main motor nucleus

parasympathetic nucleus

sensory nucleus

• Opening in skull : Internal acoustic meatus facial canal

stylomastoid foramen

Facial Nerve

Cerebral cortex

Nucleus of VI nerve

Thalamus &hypothalamic nuclei Dcending autonomic

pathway

Sensory nucleus

Main motor nucleus

Parasympathetic nuclei

Facial nerve

pons

Facial nerve nucleus & its central connections

Main motor nucleus

Nucleus part

muscle of upper muscle of lower

part of face part of face

corticonuclear fibers from corticonuclear fibers both cerebral hemispheres from opposite cerebral hemispheres

afferents afferents

Parasympathetic nuclei

Superior salivatary nucleus lacrimal nucleus

fibers from hypothalamus fibers from hypothalamus + (emotional responses)fibers from nucleus of - +tractus solitarius (taste) fibers from sensory nuclei of trigeminal nerve

afferents afferents

Sensory nucleus• Lies close to motor nucleus

• Upper part of the nucleus of tractus solitarius

Taste fibers geniculate ganglion sensory nucleus

internal thalamus and capsule hypothalamic nuclei

Corona radiata taste area of the cortex

(lower part of postcentral gyrus)

Cross midian plane

Pathway of the facial nerve

motor root sensory root(nervus intermedius)

pass posteriorly central processes of the unipolar cells of geniculate ganglion + around abducent nucleus efferent preganglionic parasympathetic fibers from parasympathetic nuclei pass anteriorly

emerge from anterior surface of brain

between the pons & medulla oblongata

Midbrain

II & optic tractIII

IV

VVI

VIIVIII

IX

XI

XIIX

Olfactory bulb Olfactory tract

Infundibulum & mamilary body

Base of the brain

Laterally –posterior cranial fossa (C VIII nerve)

internal acoustic meatus (petrous part of temporal bone)

facial canal

medial wall of tympanic cavity – nerve expands & form

sensory geniculate ganglion

grater petrosal nerve

lacrimal gland

turns backwards over promontory of middle ear

_

downwards & medial to the middle ear

Join c_

submandibular &

sublingual glands

ant. 2/3 of tongue

Parotid gland

Stylohyoid mm Post. belly of digastric mm

stylomastoid foramen

nerve to stapedius lingual nerve

chorda tympani

Parotid gland

temporal zygomatic buccal mandibular cervical

branch branch branch branch branch

Temporal branch

zygomatic branch

Buccall branch Mandibular branch

Post. auricular branch

cervical branch

Sublingual gland Subman. gland

Lingual nerve

Chorda tumpani

Nerve to stapedius

Geniculate

ganglion

Facial nerveGrater petrosal nerve

Distribution of facial nerve

Deep petrosal nerve

Nerve to pterygoid canal

Pterygopaltine

ganglionV 3

V2

Zygomaticnerve

Facial expression defects associated with lesions of UMN (1) & LMN (2)

Upper motor neuron

lesion

Lower motor neuron

lesion

Cranial Nerve Summary # Name Foramina Function

V Trigeminal V1: Sup Orb Fissure V2: Foramen Rotundum V3: Foramen Ovale

Sensory: Face 

VI Abducens Superior Orbital Fissure

VII

Facial Internal Auditory Canal

VTrigeminal

V1: Sup Orbital Fissure V2: Foramen Rotundum V3: Foramen Ovale

Sensory: Face  Motor : Mastication, Tensor Tympani, Tensor Palati  mylohyoid

VIAbducens

Superior Orbital Fissure

Motor: Lateral Rectus

VII FacialInternal Auditory Canal

Sensory: Taste (Anterior 2/3 Tongue)  Motor : Muscles Of Facial Expression Salivary Glands, Lacrimal Glands

# Name Foramina Function

Cranial Nerve Summary