Week 4.0 - Cranial Nerves Flashcards Preview

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Flashcards in Week 4.0 - Cranial Nerves Deck (62):
1

How do CNI and II differ from the rest?

-They are atypical in that they are brain tracts (outpouchings of axons)

2

What is a pneumonic to remember the cranial nerves?

-Oh, Oh, Ot, to touch and feel very good vagina ah heaven
-olfactory, optic, oculomotor, trochlear, Trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, accessory spinal, Hypoglossal

3

What is a pneumonic to remember each of the cranial nerve types?

-Some Say Marry Money but my brother says big boobs matter more
-Sensory, sensory, motor (a), motor, both, motor, both (a), sensory, both(a), both(a), motor, motor

4

Which cranial nerves originate in the midbrain?

-3/4

5

Which cranial nerves originate in the pons?

-5,6,7

6

Which cranial nerves originate in the medulla oblongata?

-8,9,10,11,12

7

Name Cranial nerve I
What type of nerve is it?
Where is it from/to?
What is its function?

-Olfactory
-Sensory
-Olfactory mucosa through cribriform plate to form olfactory bulb to olfactory tract
-Sense of smell

8

Where is cribriform plate?

-Ethmoid bone

9

What is anosmia?

-Lack of smell

10

Give 3 major causes of anosmia

-Upper respiratory tract infection
-Trauma (eg fracture cribriform plate damages nerves)
-Meningitis

11

How do you test CNI?

-Ask patient to smeel coffe/orange/smelling salts

12

Name CN II
What type of nerve is it?
Where if is from/to?
What is its function?

-optic nerve
-Sensory
-Complex pathway from the retina to optic tract through optic canal then primary visual cortex
-Sight

13

How do you test CNII?

-Visual acuity (snellen chart)
(-Colour Vision)
-Visual fields
-Pupillary reflexes
-Fundoscopy

14

Name CNIII
What type of nerve is it?
Where is it from/to?
What is its function

-Oculomotor
-Motor (parasympathetic)
-From Oculomotor nucleus (edinger-westphal nucleus) in midbrain to most extraocular muscles
-Move eyeball/eye lid (pupillary constriction)

15

Name the muscles which oculomotor nerve innervates

-Inferior oblique
-Superior, inferior, medial rectus
-Levator palpabrae Superioris
(-Pupillae constrictor)

16

Through which foramina does optic nerve pass?

-Optic canal

17

Through which foramina foes oculomotor nerve pass?

-Superior orbital fissure

18

How do you test oculomotor nerve?

-H test

19

How would a strict oculomotor nerve palsy present?

-Down and out pupil
-Ptosis

20

How will a complete oculomotor nerve palsy present?

-Down and out pupil
-Ptosis
-Myadriasis (blown pupil)

21

Name CN IV
What type of nerve is it?
Where is it from/to?
What is its function?

-Trochlear
-Motor
-From trochlear nucleus in dorsal Midbrain to superior oblique of the eye
-Look down and in (Moves the eye down when the eye is adducted - also contributes to abduction and depression although weakly)

22

What is special about trochlear nerve?

-It has the longest intracranial length

23

What structures travel through the cavernous sinus?

-CN III, IV, V(V1/V2) VI,
-Internal carotid artery

24

Through which foramina does trochlear travel?

-Superior orbital fissure

25

Why might someone wih trochlear nerve palsy have a slight head tilt?

-To compensate for the diplopia they are experiencing, especially when walking downstairs as cant look down and in

26

How might an infection in the face/sinus/teeth etc cause problems with trochlear nerve?

-Facial veins are valveless, the infection can track back to cavernous sinus -> cavernous sinus thrombosis -> life threatening needs immediate treatment

27

Name CNV
What type of nerve is it
Where is it from/to
What is its function?

-Trigeminal
-Sensory and motor
-Trigeminal nucleus in the pons, splits into 3 branches (V1/2/3)
-General sensation to the face, muscles of mastication

28

Through which foramina do the branches of trigeminal nerve travel?

-Opthalmic -> superior orbital fissure
-Maxillary -> foramen rotundum
-Mandibular -> foramen ovale

29

What is trigeminal neuralgia?

-Sensory hyperactivity of the trigeminal nerve which sends shooting/burning pain along the distribution of the nerve

30

Why is trigeminal nerve important in numbing the lower teeth?

-Inferior alveolar nerve is branck of trigeminal and is blocked to numb teeth

31

Why does the corneal reflex test trigeminal nerve?

-Ophthalmic branch of trigeminal nerve supplies sensory information from the cornea to the brain -> causes blinking reflex

32

How is trigeminal nerve assessed?

-Sensory to face
-Clench jaw for MoM

33

Name CNVI
What type of nerve is it?
Where is it from/to?
What is its function

-Abducens
-motor
-From Adbucens nucleus in pons to lateral rectus
-abduct the eye

34

Through which foramina does abducens nerve travel?

-Superior orbital fissure

35

Why is abducens said to produce a false localising sign?

-Its long course means it is the first nerve to be susceptible to raised intracranial pressure which can produce symptoms of abducens palsy but does not necessarily mean that this is where the lesion is

36

How is abducens nerve tested?

-H test -> cannot abduct eye

37

Name CNVII
What type of nerve is it?
Where is it from/to?
What is its function?

-Facial Nerve
-Special sensory, motor (Parasympathetic)
-Facial nucleus in medulla oblongata through internal auditory meatus -> facial canal -> sytlomastoid foramen -> parotid gland -> splits into 5 branches -> temporal, zygomatic, buccal, maxillary, cervical
-Special sensory to anterior 2/3 tongue (chorda tympani), muscles of facial expression (salivation and lacrimation)

38

When is facial nerve said to be extracranial?

-After stylomastoid foramen

39

Which salivary glands does facial nerve (chorda typani) serve?

-Submandibular
-Sublingual

40

Through which foramina does facial nerve travel?

-Internal acoustic meatus

41

What is bells palsy? What is thought to be the most common cause?

-Idiopathic unilateral facial paralysis
-Inflammation at stylomastoid foramen

42

How do you examine facial nerve?

-Facial movements
-Taste

43

Name CN VIII
What type of nerve is it?
Where is it from/to?
What is its function?

-Vestibulocochlear (acoustic nerve)
-Sensory
-Cerebellopontine angle branches into cochlear nerve to cochlea and vestibular nerve to semilunar canals (inner ear)
-Hearing(cochlear) and balance(vestibular)

44

Through which foramina does vestibulocochlear nerve travel?

-Internal acoustic meatus

45

What is a vestibular schwannoma (acoustic neuroma)?

-benign intracranial tumour of myelin sheath of vestibulocochlear nerve causing sensorineural hearing loss, tinnitus, balance disruptions and rarely facial palsy if the tumour is v large

46

How do you examine CN VIII?

-Whisper in ear/rub fingers
-Rinne and weber's tuning fork test

47

How do you tell the difference between conductional and sensoryneural hearing loss?

-Rinne and Weber's
-In rinne test a conduction block will produce a louder sound on affected side, whilst a sensorineural block will be louder on the opposite side
-In Weber's test a conduction block will be louder through bone on the effected side
Using both tests together to determine the type of block

48

How many pairs of cranial and spinal nerves?

-Cranial = 12
-Spinal = 31

49

Name CNIX
What type of nerve is it?
Where is it from/to?
What is its function?

-Glossopharyngeal
-Sensory, Motor (parasympathetic)
-From medulla oblongata to tongue, parotid, carotid sinus and stylopharyngeus
-Provides sensation to oropharynx, post 1/3 tongue, carotid sinus body
-Motor to stylopharyngeus
-(parasympathetic input to parotid gland)

50

Through which foramen does glossopharyngeal pass?

-Jugular foramen

51

How do you test CNIX?

-Gag (pharyngeal) reflex for afferent branch
-Swallow for efferent branch

52

Name CNX
What type of nerve is it?
Where is it from/to?
What is its function?

-Vagus nerve
-Sensory, motor (parasympathetic)
-From medulla oblongata to everywhere
-Provides sensation to laryngopharynx, ear
-Provides motor supply to muscles of pharynx and larynx
-(parasympathetic input to heart, lungs, GI tract)

53

Describe the path of the left and right recurrent laryngeal nerves

-Left loops around arch of aorta
-Right loops around right subclavian

54

Through which foramen does the vagus nerve pass?

-jugular foramen

55

How do you test CNX?

-Gag reflex/carotid sinus massage tests efferent branch
-Swallow to test motor

56

Name CNXI
What type of nerve is it?
Where is it from/to?
What is its function?

-Accessory spinal nerve
-Motor
-Spinal roots C1-C5 to SCM and trapezius
-Innervates SCM and trapezius

57

Through which foramina does accessory spinal nerve pass?

-Through foramen magnum into the cranium then through the jugular foramen back out

58

What is different about spinal accessory nerve than other CNs?

-Has a spinal portion and a cranial portion
(cranial part is short and often considered part of vagus)

59

How do you examine CNXI?

-Look for wasting or trapezius and SCM?
-Rotate head against resistance
-Shrug shoulders against resistance

60

Name CNXII
What type of nerve is it?
Where is it from/to?
What is its function?

-Hypoglossal nerve
-Motor
-Hypoglossal nucleus in medulla oblongata to tongue
-Extrinsic and intrinsic muscles of the tongue

61

Through which foramen does hypoglossal travel?

-hypoglossal canal

62

How do you test CNXII?

-Get the patient to stick tongue out, look for fasciculations and deviations towards one side