Session 5- Cranial Nerves continued

Question 1

what are the divisions of the trigeminal nerve

Answer 1

opthalmic
maxillary
mandibular

Question 2

which branches of the trigeminal nerve pass through the cavernous sinus

Answer 2

opthalmic and maxillary

Question 3

what does the opthalmic nerve pass through

Answer 3

superior orbital fissure

Question 4

what does the maxillary pass through

Answer 4

foramen rotundum

Question 5

what does the mandibular pass through

Answer 5

foramen ovale

Question 6

what kind of nerve is the CN V

Answer 6

motor and general sensory

trigeminal

Question 7

what are the distal branches of the Va branch of trigeminal

Answer 7

opthalmic

• frontal nerve- which gives rises to supraorbital/supratrochlear
• nasocillary nerve

Question 8

what is the distal branch of the Vb

Answer 8

maxillary

=infra-orbital and superior alveolar nerves

Question 9

what is the distal branch of Vc

Answer 9

• auriculotemporal nerve
• lingual nerve
• inferior alveolar nerve and mental nerve

Question 10

where does the trigeminal nerve originate

Answer 10

pons

Question 11

in varicella zoster infections where does it lie dormant

Answer 11

trigeminal ganglion then reactivates through one of the divisions usually opthalmic

causes a vescicular type rash that remains in the dermatome of the opthalmic branch

Question 12

what is hutchinson sign

Answer 12

vescicular rash only extends down the nose if the nasocilary branch is involved

this increases the likelihood of eye being affected which threatens sight

Question 13

what is CN VII

Answer 13

facial nerve

Question 14

what kind of nerve is CN VII

Answer 14

motor, special sensory- taste, parasympathetic

Question 15

which of the cranial nerves are parasympathetic

Answer 15

1973

X IX VII III

Question 16

Where does the facial nerve originate

Answer 16

pons

specifically pontomedullary junction

Question 17

target tissues of CN VII

Answer 17

muscles of facial expression
taste from ant 2/3 of the tongue
glands - lacrimal, salivary (not parotid), mucosal (nose) not sweat

Question 18

how do we test if CN VII is intact

Answer 18

facial expressions

unilateral facial droop +/- reporting symptoms due to absence of the other facial nerve functions

Question 19

route of facial nerve

Answer 19

pons- internal acoustic meatus - into petrous bone and here gives off 3 branches - enters through base of skull via sylomastoid foramen - gives off extra cranial branches= muscles of facial expression

Question 20

what are the three intrapetrous branches of the facial nerve

Answer 20

greater petrousal nerve - supplies lacrimal, masal and oral glands

nerve to stapedius

corda tympani- carries special sensory info from ant 2/3 of tongue
parasymoathetic fibres run with it to get to yhe glands in the oral cavity- salivary

Question 21

where does the facial nerve exit the skull

Answer 21

stylomastoid foramen

Question 22

how do we differentiate between a stroke and nerve lesion in terms of facial drooping

Answer 22

forehead sparing in a stroke because forehead receives motor innervation from both hemispheres of the cerebral cortex. A stroke that compromised motor innervation of the face would therefore only result in paralysis of the lower half of the face

Question 23

how does pathology involving the motor pathways anywhere along the path from the PMC to where synapse with facial nerve motor nuclei present- before it exists the brainstem

Answer 23

upper half of contralateral face spared- has back up from ipsilateral input due to dual innervation

forehead wrinkles

Question 24

how does pathology or imjury of the facial nerve anywhere from exit from the brainstem present and along its way to muscle tissue

Answer 24

whole half ipsilateral face is drooped no back up as it has already exited the brainstem

Question 25

CN VIII

Answer 25

Vesticulocochlear

Question 26

what kind of nerve is CNVIII

Answer 26

special sensory

Question 27

where does the CN VIII originate

Answer 27

pons

Question 28

target tissues of CN VIII

Answer 28

vestibular system | cochlea

Question 29

route of CN VIII

Answer 29

exits pons-pontomedullary junction- then travels through internal acoustic meatus into the inner ear to the vestibular system - balance- and cochlea- hearing

Question 30

how do we test if the CN VIII works

Answer 30

hearing tests

Question 31

route of CN IX and X

Answer 31

arise from medulla run through posterior cranial fossa exit through jugular foramen enter into carotid sheath

Question 32

what kind of nerve is CN IX

Answer 32

glossopharyngeal- mainly sensory

Question 33

target tisses of CN IX

Answer 33

post 1/3 of tongue- Somatosensory and Genreal sensory 1 swallowin muscle afferents from carotid sinus and body parasymoathetic to parotid

Question 34

what is the function of the soft palate

Answer 34

separates the nasal cavity from the oral cavity

Question 35

what type of nerve is CN X

Answer 35

motor and sensory

Question 36

target tissues of CN X

Answer 36

muscles of larynx/ pharynx- including soft palate sensory- larynx and laryngopharynx parasympathetic to many tissues

Question 37

where do CN IX and X emergr

Answer 37

medulla

Question 38

how do patients present if they have lesions to CN X and CN IX

Answer 38

difficulty swallowing weak cough difficulties with speech or changes to voice

Question 39

how do we asesess if cranial nerve X and IX is working

Answer 39

speech swallow cough soft palate movement and uvula position

Question 40

uvula position if nerve lesion

Answer 40

if lesion is left side uvula goes off centre

Question 41

where do CN XI XII emerge and what route do they take

Answer 41

medulla and run through the posterior cranial fossa they then enter the carotid sheath briefly hypoglossal then exits and travels to the tongue accesory exits and heads towards posterior triangle

Question 42

what type of nerve is hypogolssal

Answer 42

motor

Question 43

target tissue of CN XII

Answer 43

tongue

Question 44

where does the hypoglossal nerv exit

Answer 44

hypoglossal canal and at the level of the mandible it superficially crosses the internal and external carotid arteries

Question 45

if there is damage to the right CN XII where does the tongue deviate

Answer 45

lick your wound | deviates towards weaker side therefore right

Question 46

what kind of nerve is teh accesory nerve

Answer 46

motor

Question 47

where does CN XI emerge

Answer 47

medulla

Question 48

target tissues of CN XI

Answer 48

SCM | Trapezius