Download MBBS Anatomy PPT 39 Facial Nerve Notes

Cranial nerves

?

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Largest cranial nerve ? trigeminal

?

Longest cranial nerve ? vagus

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?

m/c paralyzed ? facial nerve

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?

m/c involved in intracranial lesions- abducent

?

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Longest ? Intracanalicular course- facial

?

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Dorsal aspect of brain- trochlear - most slender

?

Only motor branch of 9th cranial nerve ?

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Stylopharyngeus

?

True peripheral n except- optic tract

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?

Monosynaptic reflex in brain ? jaw jerk/masseteric
reflex

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Cranial Nerves

Figure 13.4a

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Location of cranial nerves

?Anterior cranial fossa: C.N. 1?2

?Middle cranial fossa: C.N. 3-6

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?Posterior cranial fossa: C.N. 7-12

Sensory nerve
?Olfactory (1)

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?Optic (2)

?Vestibulocochlear (8)
Motor nerve

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?Oculomotor (3)

?Trochlear (4)

?Abducens (6)

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?Accessory (11)

?Hypoglossal (12)

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Mixed nerves
?Trigeminal (5)

?Facial (7)

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?Glossopharyngeal (9)

?Vagus (10)

Innervation of Branchial arch

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muscles ?Mixed nerves

?1 - Trigeminal

?2 - Facial

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?3 - Glossopharyngeal

?4 ? Vagus - SLN

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?5 ? Regresses

?6 ? Vagus - RLN

Cranial Nerve VII: Facial

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? Fibers leave lower pons,
? travel through internal acoustic meatus,
? emerge through stylomastoid foramen
? to lateral aspect of face

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? Pass through Parotid gland
? Mixed nerve with five major branches
? Motor functions include facial expression,
? autonomic impulses to lacrimal & salivary glands
? Sensory function is taste from anterior two-thirds of

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tongue ? Chorda tympani n


Cranial Nerve VII: Facial

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Table 13.2(VII)

Facial colliculus

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1. Motor nucleus of facial nerve (facial nucleus)

2nd branchial arch muscles muscles of facial
expression .

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2. Superior salivatory nucleus - To chorda tympani

branch joins lingual branch of Lingual n -V3 - in
Infratemporal fossa submandibular ganglion

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submandibular, sublingual & acc lingual glands

3. Lacrimal nucleus - greater petrosal branch +

deep petrosal n - pterygopalatine ganglion

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Lacrimal glands & paranasal sinuses

1. Geniculate ganglion

Central processes nervus intermedius

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Peripheral processes chorda tympani, greater petrosal and

deep petrosal nn vidian nerve Pterygopalatine ganglion.

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(some fibers join the auricular branch of the vagus)

2. Gustatory nucleus - nucleus of tractus solitarius

3. Nucleus of spinal trigeminal tract - From nervus

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intermedius


Taste

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Taste sensations

? Facial N.

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? Glossopharyngeal N.

? Vagus N.

? Nucleus tractus solitarious

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Parasympathetic ganglion

Ciliary ganglion

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Pterygopalatine ganglion

Submandibular ganglion

Otic ganglion

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Facial palsy-S.N.Palsy.

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? CVA-internal capsule - HT
? Cortico nuclear- cortico - bulbar fibers are

involved

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? Loss of movement of lower half of face on

opposite side of lesion

? Upper half of face escapes b/of bilateral

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representation in cortex

? NUCLEAR PALSY-LMN type of palsy of same

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side upper & lower half with ipsilateral 6th
nerve palsy ie internal squint? LR6

Facial nerve palsy

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Millard Gubler syndrome - contralateral

hemiplegia & ipsilateral facial palsy b/of
pontine lesion- affects pyramidal tract &
facial nucleus.

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Infra nuclear palsy - bells palsy - LMN Palsy -

same side complete face paralysis.

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Internal acoustic meatus- LMN Palsy &

deafness-8th cr n.

Lesion at genu ? geniculate ganglion -

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diminished lacrimation