Anatomy Head

Question 1

what nerve injury causes impaired tear secretion

Answer 1

greater petrosal nerve (from facial nerve)

Question 2

Where do the cranial nerves arise from

Answer 2

1+2 from cerebrum
Rest from brainstem
3 midbrain pontine junction
4 midbrain
5 pons
6 - 8 pontine medulla junction
8 - 11 medulla oblongata posterior to olive
12 medulla anterior to olive

Question 3

What cranial nerves exit through canals

Answer 3

2 + 12

Question 4

CN1

Answer 4

olfactory

Question 5

CN2

Answer 5

optic

Question 6

CN3

Answer 6

oculomotor

Question 7

CN4

Answer 7

trochlear

Question 8

CN5

Answer 8

trigeminal

Question 9

CN6

Answer 9

abducens

Question 10

CN7

Answer 10

facial

Question 11

CN8

Answer 11

vestibulocochlear

Question 12

CN9

Answer 12

glossopharyngeal

Question 13

CN10

Answer 13

vagus

Question 14

CN11

Answer 14

spinal accessory

Question 15

CN12

Answer 15

hypoglossal

Question 16

CN1 exit and function

Answer 16

cribriform plate

smell

Question 17

CN2 exit and function

Answer 17

optic canal

vision

Question 18

CN3 exit and function

Answer 18

superior orbital fissure
4 extrinsic eye muscles (superior, medial and inferior rectus, inferior oblique) and levator palpebrae superioris
+ pupillary sphincter (constricts pupil)

Question 19

CN4 exit and function

Answer 19

superior orbital fissure

contralateral superior oblique muscle

Question 20

CN5 exit and function

Answer 20

ophthalmic V1:
superior orbital fissure
sensation to scalp, forehead, cornea, nose

maxillary V2:
foramen rotundum
sensation to cheeks, lower eye lid, nasal mucosa, upper lip, upper teeth, palate

mandibular V3:
foramen ovale
sensation to anterior 2/3 tongue, skin over mandible, lower teeth, chin
+ muscles of mastication

Question 21

CN6 exit and function

Answer 21

superior orbital fissure

lateral rectus muscle

Question 22

CN7 exit and function

Answer 22

internal acoustic meatus > stylomastoid foramen
sensation to part of external ear + taste from anterior 2/3 tongue, hard and soft palate
+ muscles of facial expression
+ lacrimal, submandibular, sublingual glands and mucous glands of mouth and nose

Question 23

CN8 exit and function

Answer 23

internal acoustic meatus

hearing and balance

Question 24

CN9 exit and function

Answer 24

jugular foramen
sensation to posterior 1/3 tongue, external ear, and middle ear cavity
\+ carotid body and sinus
\+ taste from post. 1/3 tongue
\+ parotid gland, stylopharyngeus

Question 25

CN10 exit and function

Answer 25

jugular foramen sensation to external ear, larynx and pharynx + sensation from larynx, pharynx and, thoracic & abdominal viscera + taste from epiglottis region of tongue + smooth muscles of pharynx, larynx and most of the GIT, most muscles of pharynx and larynx.

Question 26

CN11 exit and function

Answer 26

jugular foramen | trapezius and sternocleidomastoid

Question 27

CN12 exit and function

Answer 27

hypoglossal canal | intrinsic and extrinsic tongue muscles (except the palatoglossus)

Question 28

What nerve is surrounded by cranial meninges

Answer 28

Optic nerve | unlike other nerves surrounded by epi-, peri- and endoneurium

Question 29

cavernous sinus thrombosis can cause which nerve palsy

Answer 29

oculomotor and abducens | they travel through the cavernous sinus

Question 30

oculomotor nerve palsy features

Answer 30

ptosis (drooping upper eyelid) down and out position of eye dilated pupil

Question 31

trochlear nerve palsy

Answer 31

diplopia | head tilt away from affected side

Question 32

muscles concerned in corneal reflex

Answer 32

V1 of trigeminal as afferent | facial as efferent

Question 33

abducens nerve palsy

Answer 33

affected eye resting in adduction

Question 34

where does the facial nerve divide into 5 terminal branches

Answer 34

within parotid gland

Question 35

what are the facial nerve branches

Answer 35

``` Temporal branch Zygomatic branch Buccal branch Marginal mandibular branch Cervical branch ``` responsible for innervating muscles of facial expression

Question 36

intracranial vs extracranial lesions to facial nerve features

Answer 36

intracranial: muscle of facial expression weakened or paralyzed + chorda tympani - reduced salivation and loss of taste on the ipsilateral 2/3 of the tongue OR nerve to stapedius – ipsilateral hyperacusis (hypersensitive to sound) OR greater petrosal nerve – ipsilateral reduced lacrimal fluid production extracranial: only weakness of muscles NB: if no cause found --> Bell's palsy

Question 37

otitis media complications

Answer 37

infection of middle ear - otitis media with effusion --> glue ear, decrease in hearing - mastoiditis --> infection of air cells - meningitis --> when mastoiditis spreads to the middle cranial fossa and into the brain

Question 38

meniere's disease

Answer 38

disease of inner ear episodes of vertigo, low-pitched tinnitus, hearing loss excess accumulation of endolymph in membranous labyrinth --> damage thin membranes of ear that detect balance and sound

Question 39

levator palpebrae superioris function and innervation

Answer 39

elevates the upper eyelid | oculomotor nerve

Question 40

superior and inferior rectus muscles function and innervation

Answer 40

superior: elevates eye inferior: moves eye downwards both innervated by oculomotor nerve

Question 41

medial and lateral rectus function and innervation

Answer 41

medial: adducts eye --> oculomotor nerve lateral: abducts eye --> abducens nerve

Question 42

superior and inferior oblique function and innervation

Answer 42

superior: down and out --> trochlear inferior: up and out --> oculomotor

Question 43

mnemonic for extraocular muscles innervation

Answer 43

LR6 - SO4 - R3

Question 44

what are the 4 paranasal sinuses

Answer 44

frontal, ethmoid, sphenoid, maxillary

Question 45

how does maxillary sinusitis cause toothache

Answer 45

maxillary nerve supplies both maxillary sinus and upper teeth

Question 46

upper respiratory tract infection can spread where

Answer 46

- middle ear through auditory tube opening - sinuses (continuous with nasal cavity) - cavernous sinus thrombosis, meningitis or brain abscess (communication between cavernous sinus, facial vein, superior ophthalmic vein)

Question 47

cribriform plate fracture features

Answer 47

- can penetrate the meningeal linings of the brain, causing leakage of CSF - exposing brain to the outside environment increases risks of meningitis, encephalitis and cerebral abscesses - olfactory bulb damage as it sits on cribriform plate --> anosmia

Question 48

what are the salivary glands

Answer 48

parotid, sublingual, submandibular

Question 49

what passes through parotid gland

Answer 49

facial nerve, retromandibular vein, external carotid artery (in gland, gives rise to posterior auricular artery, then terminates in maxillary artery and superficial temporal artery)

Question 50

what is a ranula

Answer 50

type of mucocele (mucous cyst) that occurs in the floor of the mouth inferior to the tongue, most common disorder of sublingual glands due to their higher mucin content in secretions compared to other salivary glands

Question 51

what nerves are in close relation to submandibular gland

Answer 51

lingual, hypoglossal, facial nerve (marginal mandibular branch)

Question 52

which salivary gland is most susceptible to calculi and why

Answer 52

submandibular | cause: torturous length of the duct (5cm), ascending secretory pathway, nature of salivary secretion

Question 53

what is the nature of each salivary gland secretion

Answer 53

parotid: serous sublingual: predominantly mucous (mucin) submandibular: mixed serous and mucous

Question 54

gag reflex nerves involved

Answer 54

glossopharyngeal as afferent | vagus as efferent

Question 55

what structures are in danger in case of TMJ dislocation

Answer 55

facial and auriculotemporal (from V3) nerves

Question 56

All innervations of tongue

Answer 56

post 1/3 sensation and taste by glossopharyngeal | Ant 2/3 sensation by V3 mandibular, taste by facial chorda tympani