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Flashcards in Anatomy of Cranial Nerve Testing Deck (109)
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1
Q

CN V1

A

SENSORY

2
Q

CN V2

A

SENSORY

3
Q

CN V3

A

SENSORY + MOTOR

4
Q

Where is the intracranial part of the CNS between?

A

Between the point of connection of the CNS and their respective base of skull foraminae

5
Q

What are the 3 divisions of the trigeminal nerve? What fibres do they contain?

A

CN V1 - ophthalmic - sensory
CN V2 - maxillary - sensory
CN V3 - mandibular - sensory and motor

6
Q

What is the only cranial nerve to attach to the pons?

A

CN V

7
Q

Where does CN V attach in the intra-cranial cavity?

A

Pons

8
Q

Describe the attachment of CN V to the pons?

A

Laterally

Half way between the midbrain and medulla

9
Q

Name the only nerve in the anterior cranial fossa.

A

CN I (olfactory)

10
Q

What is the function of the olfactory nerve?

A

Sensory - smell

11
Q

Describe the extra cranial part of CN I.

A

Sensory so on body wall

Lays within olfactory mucosa of nasal cavity

12
Q

What is the location of the cranial fossa of CN I?

A

Cribiform plate of ethmoid bone

Anterior cranial fossa

13
Q

What is the intracranial part of CN I (i.e CNS connection)?

A

Olfactory nerves synapse in the olfactory bulb

Then pass through the olfactory tract

14
Q

What is the function of the optic nerve (CN II)?

A

Sensory - vision

15
Q

Describe the extra-cranial part of CN II.

A

Neurons of the retina travel posteriorly via the optic nerve from the posterior hemisphere of the eye through the orbit

16
Q

What is the location of the cranial fossa of CN II?

A

Optic nerve possess through optic canal

Middle cranial fossa

17
Q

What is the intracranial part of CN II?

A

Travels around pituitary stalk to optic chiasm to form the optic tract

18
Q

Where is the connection of CN II to the CNS?

A

Diencephalon

19
Q

How is CN I tested?

A

Note: not done routinely

Ask the patient to smell a familiar smell e.g lemon while covering the contralateral nostril

20
Q

List the 5 ways that CN II can be tested.

A
  1. Acuity
  2. Colour
  3. Fields
  4. Reflexes
  5. Fundoscopy
21
Q

What is the function of CN III?

A

Sensory and Motor
Eye movement - motor
Pupil constriction - parasympathetic

22
Q

Where does CN III connect with the CNS?

A

Midbrain

23
Q

What is the intracranial part of CN III?

A

Travels towards the orbit in the lateral walls of the cavernous sinus

24
Q

What is the location of the cranial foraminae of CN III?

A

Superior orbital fissure

25
Q

Describe the extra-cranial part of CN III?

A

Passes through SOF into orbit to supply extraoccular muscles

26
Q

Where do parasympathetics of CN III synapse? What is their function?

A

Ciliary ganglion

Pupillary constriction

27
Q

How is CN III tested?

A

Shine a light into the patient’ eyes to check for pupillary constriction

28
Q

Where does CN IV connect to the CNS?

A

Midbrain

29
Q

Describe the intracranial part of CN IV?

A

Travels towards the orbit in the lateral wall of the cavernous sinus

30
Q

Where is the location of the cranial foraminae of CN IV?

A

Superior orbital fissure

31
Q

Describe the extra-cranial course of CN IV?

A

Travels through SOF into orbit to supply only 1 muscle

32
Q

What muscle is supplied by CN IV?

A

Superior oblique

33
Q

At what junction does CN VI connect with the CNS?

A

Pontomedullary junction

34
Q

Describe the intracranial course of CN VI?

A

Travels towards the orbit within the cavernous sinus

35
Q

Where is the cranial foraminae of CN VI located?

A

Superior orbital fissure

36
Q

Describe the extra cranial course of CN VI.

A

Passes through SOF into orbit to supply only the LATERAL RECTUS muscle

37
Q

What artery runs close to CN VI?

A

Internal carotid artery

38
Q

How is CN VIII tested?

A

Rinnie and webber

39
Q

Describe the extra cranial course of CN VIII.

A

Axons from vestibular and cochlear apparatus

40
Q

Where is the cranial foramina of CN VIII located?

A

Posterior cranial fossa
Internal acoustic meatus
think ‘acoustic is sound’

41
Q

At what junction does CN VIII connect to the CNS?

A

Pontomedullary junction

42
Q

Describe the intracranial course of CN VIII.

A

Travels posteromedially from the internal acoustic meatus to the pontomedullary junction

43
Q

What is the function of CN VIII?

A

SENSORY

Hearing and balance

44
Q

Describe the function of CN XI (spinal accessory).

A

MOTOR - to sternocleidomastoid and trapezius

45
Q

Where does CN XI connect with the CNS?

A

Spinal cord (cervical part)

46
Q

Outline the intracranial course of CN XI.

A

Ascends through foramen magnum then travels towards jugular foramen

47
Q

What part of the cranial fossa would you find CN XI?

A

Posterior

48
Q

What is the location of the cranial foramina of CN XI?

A

Jugular foramen

Posterior cranial fossa

49
Q

Outline the extra cranial course of CN XI.

A

Axons supply SCM on deep surface then go across the posterior triangle to supply trapezius and sternocleidomastoid

50
Q

How is CN XI tested?

A
  1. Ask patient to shrug shoulders (should be the same on both sides)
  2. Ask them to turn head to flex neck and turn to opposite side
51
Q

What is the function of CN XII?

A

Motor - to muscles of the tongue

52
Q

Where is the connection of CN XII to the CNS?

A

Via many rootlets lateral to the pyramids of the MEDULLA OBLONGATA

53
Q

Describe the intracranial course of CN XII?

A

Passes anteriorly to the hypoglossal canal

54
Q

What is the location of the cranial foramina of CN XII?

A

Hypoglossal canal

Posterior cranial fossa

55
Q

Describe the extracranial part of CN XII?

A

Descends lateral to the carotid sheath

At level of hyoid, it turns anteriorly towards lateral aspect of the tongue to supply muscles of the tongue

56
Q

CN XII supplies all tongue muscles except?

A

Palatoglossus

57
Q

How is CN XII tested?

A

Ask patient to stick tongue straight out
If both CNXII’s are functioning normally the tongue tip remains in the midline on protrusion
If there is unilateral CN XII pathology the tongue tip will point towards the side of the injured nerve

58
Q

Where does CN V connect with the CNS?

A

Pons

59
Q

Describe the intracranial part of CN V and its location in the cranial fossa.

A

Inferior to the tentorium cerebelli between the MIDDLE and POSTERIOR cranial fossa

60
Q

What is the location of the cranial foramina for CN V1?

A

SOF

61
Q

What is the location of the cranial foramina for CN V2?

A

Foramen rotundum

62
Q

What is the location of the cranial foramina for CN V3?

A

Foramen ovale

63
Q

Describe the extra cranial course of CN V.

A

From structures of the face to the foramina

CN V3 - from foramen ovale to appropriate muscle

64
Q

What does CN V1 supply sensory innervation to?

A

Upper eyelid
Cornea
Conjunctiva
Skin on roof, bridge and tip of nose

65
Q

What does CN V2 supply sensory innervation to?

A

Skin on lower eyelid
Skin on maxilla
Skin on ala of nose
Skin of upper lip

66
Q

What does CN V3 supply sensory innervation to?

A

Skin of mandible

Skin around TMJ

67
Q

What area of skin does CN V3 not supply sensory innervation to?

A

Skin on the angle of the mandible

68
Q

What nerve supplies the skin on the angle of the mandible?

A

Greater auricular nerve

C2, C3

69
Q

What muscles does CN V3 supply? What do each of the muscles do?

A

Masseter (close)
Temporalis (close)
Medial pterygoid (close)
Lateral pterygoid (open)

70
Q

Outline how CN V sensory innervation is tested.

A
  1. Ask the patient to close their eyes
  2. Gently brush the skin in each dermatome with a fine tip of cotton wool
  3. Ask the patient to tell you when they feel their skin being touched
  4. Compare the 2 sides

Basically, think about all the areas of the face supplied by each division and touch it

71
Q

Outline how CN V motor innervation is tested.

A
  1. Palpate the strength of contraction of the masseter & temporalis by asking patient to clench their teeth
  2. Ask the patient to open their jaw against resistance
72
Q

What is the function of the facial nerve?

A

Sensory (taste)
Motor
Parasympathetics

73
Q

At what junction does CN VII connect to the CNS?

A

Pontomedullary

74
Q

Outline the intracranial course of CN VII.

A

Directly into internal acoustic meatus

Posterior cranial fossa

75
Q

What is the location of the cranial foramina of CN VII to enter and leave and what bone is this in?

A

Internal acoustic meatus (IN)
Stylomastoid foramen (OUT)
Temporal bone

76
Q

Describe the extra cranial part of CN VII.

A

Motor axons pass into the parotid gland then to 1 of 5 branches that supply muscles of facial expression

77
Q

What does CN VII provide sensory info to? What branch is this via?

A

Anterior 2/3rds of tongue
Chorda tympani branch
Taste

78
Q

What part of the temporal bone does CN VII pass through?

A

Petrous part

79
Q

CN VII has parasympathetic fibres. What do these supply?

A

Submandibular and sublingual salivary glands

80
Q

CN VII provides motor innervation to the smallest muscle in the body, name this muscle.

A

Strapedius

81
Q

How can CN VII be tested? (note: you are testing the muscles of facial expression)

A
Ask patient to:
Raise eyebrows
Close eyes tightly
Smile
Puff out cheeks and hold air
82
Q

Outline the 5 main functions of CN IX.

A
Special sensory (taste)
Sensory
Motor
Visceral afferent
Parasympathetics
83
Q

Where does CN IX connect to the CNS?

A

Medulla oblongata

84
Q

Describe the intracranial part of CN IX.

A

Directly towards jugular foramen in posterior cranial fossa

85
Q

What is the cranial foramina for CN IX?

A

Jugular foramen

86
Q

Describe the extra cranial course of CN IX. State where it goes to and from.

A
Descends towards pharynx and the mouth
To the stylopharyngeus muscle
To the parotid gland
From pharyngeal mucosa
From carotid body and sinus
From posterior 1/3rd of tongue
87
Q

How can CN IX be tested?

A

By eliciting the gag reflex (naughty)

88
Q

Where does CN IX provide special sensory info to (taste)?

A

Posterior 1/3rd of the tongue

Vallate papillae

89
Q

Where does CN IX provide parasympathetic innervation to?

A

Parotid gland

90
Q

What nerve provides innervation to the parotid gland?

A

CN IX

91
Q

What muscle does CN IX supply?

A

Stylopharyngeus

92
Q

What does CN IX supply visceral afferent info from (sensory of organs)?

A

Carotid sinus baroreceptors

Carotid body chemoreceptors

93
Q

What does CN IX supply sensory innervation to?

A

The posterior 1/3rd of the tongue
The mucosa of most of the nasopharynx and oropharynx
The mucosa of some of the laryngopharynx (some overlap with CN X territory)
The palatine tonsil
The eustachian tube
The middle ear cavity

94
Q

What are the 4 functions of the vagus nerve?

A

Sensory
Motor
Visceral afferent
Parasympathetic

95
Q

Where does CN X connect to the CNS?

A

Medulla

96
Q

Describe the intracranial course of CN X.

A

Towards jugular foramen

Posterior cranial fossa

97
Q

Describe the extracranial course of CN X.

A

LOTS of places between palate and midgut

98
Q

Where does CN X enter and exit the cranial cavity?

A

Jugular foramen

99
Q

Where does CN X run within the neck?

A

Carotid sheath

100
Q

CN ? runs inferiorly into the thorax then gives off the recurrent laryngeal nerve to turn back superiorly to supply the muscles of the larynx

A

CN X

101
Q

Left recurrent laryngeal nerve curves under the?

A

Arch of the aorta

102
Q

Right recurrent laryngeal curves under the?

A

Right subclavian artery

103
Q

Where do both CN X’s pass to after the neck?

A

Through the diaphragm with the oesophagus

104
Q

Both CN X’s pass anterior to the lung root

A

FALSE

Posterior

105
Q

Where do the very last axons of CN X pass onto?

A

Splenic flexure of the colon

106
Q

How do you test CN X (via muscles of the palate)?

Explain the results.

A

Ask patient to say ‘ahhhhh’
Motor function
Uvula should lift straight up in midline
Unilateral pathology will pull uvula away from the non-functioning side

107
Q

How do you test CN X (via pharyngeal muscles)?

Explain the results.

A

Ask the patient to swallow some water
Watch larynx movement
Splutter may suggest abnormal swallow

108
Q

How do you test CN X (via laryngeal muscles)?

Explain the results.

A

Listen to speech

Hoarseness may suggest abnormal function of muscles of larynx

109
Q

S3, S4, S5 is a….

A

Bull’s eye to the anus lol