Lecture 44 - Cranial Nerves 1 & 2 Flashcards

1
Q

T/F: cranial nerves are classified as part of the peripheral nervous system

A

TRUE

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2
Q

which cranial nerves carry parasympathetic motor fibers?

A

CN 3, 7, 9, and 10

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3
Q

Firulais, a terrier mix, is showing signs of a CNS lesion. He displays a normal response to the menace response test in both eyes, and an absent pupillary light reflex (PLR) in the left eye. You also notice lateral strabismus in the left eye. Tapping on the medial and lateral canthus of the left eye does not elicit a response, nor does manipulating the whiskers on the left side of the maxilla. Pinching the skin on the left side of the mandible also does not elicit a response.

Which cranial nerve(s) are showing deficits in little Firulais?

A

CN 3 and 5

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4
Q

You are presented with a cat whose owner is reporting that she has been coughing and hacking when trying to eat and drink. Testing her gag reflex shows that the reflex is absent. The tongue responds to stimulation and seems to move normally. Her vocalizations also seem normal, and the owner is reporting normal bowel movements/urination.

Which cranial nerve(s) are showing a deficit?

A

glossopharyngeal (9)

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5
Q

what does the nucleus refer to

A

collection of cell bodies in the CNS

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6
Q

T/F: spinal nerves are always sensory

A

FALSE - always mixed function

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7
Q

Give the cranial nerve in the:

telencephalon

A

CN 1

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8
Q

give the cranial nerve in the:

diencephalon

A

CN 2

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9
Q

give the cranial nerve in the:

mesencephalon

A

CN 3 and 4

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10
Q

give the cranial nerve in the:

metencephalon

A

CN 5

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11
Q

give the cranial nerve in the:

myelencephalon

A

CN 6 - 12

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12
Q

what travels through the optic canal

A

optic nerve (CN 2)

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13
Q

what travels through the orbital fissure

A

oculomotor n. (CN 3)
trochlear n. (CN 4)
ophthalmic branch of CN 5
abducent (CN 6)

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14
Q

what travels through the round foramen

A

maxillary n. branch of CN 5

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15
Q

what travels through the tympano-occipital fissure

A

glossopharyngeal n. (CN 9)
vagus n. (CN 10)
Accessory n. (CN 11)

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16
Q

regular motor

A

to striated muscle

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17
Q

autonomic motor

A

parasympathetic to glands and smooth muscle

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18
Q

general sensory

A

nerves to brain

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19
Q

special sensory

A

nerves to the brain for smell, sight, taste, hearing, and balance

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20
Q

what is the function of CN 1?

A

olfactory (smell) - special sensory

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21
Q

what does CN 1 pass-through

A

cribriform plate

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22
Q

if CN 1 is damaged what happens

A

anosmia (loss of sense of smell)

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23
Q

what is the optic chiasm?

A

crossing of optic n. fibers

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24
Q

what is the function of CN 2 (optic)?

A

sight - special sensory

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25
Q

what is unique about the optic n.

A

extension of the brain rather than an actual nerve

26
Q

what does the menace response test

A

CN 2 and 7

27
Q

what does the pupillary light response test

A

CN 2 and 3

28
Q

if the CN 2 is damaged what happens

A

no menace/pupillary response

29
Q

what is innervated by CN 3 (oculomotor n.)

A

levator palpebrae superioris m.
dorsal rectus m.
medial rectus m.
ventral rectus m.
ventral oblique m.
constrictor pupillae m.

30
Q

if the eye appears to be pulled laterally, what muscle is not correctly working

A

medial rectus m.

31
Q

ptosis is caused by what muscle

A

levator palpebrae

32
Q

anisocoria

A

dilated eye

33
Q

what part of the oculomotor nerve is parasympathetic

A

the branch going to the ciliary body and constrictor pupillae m.

34
Q

what is innervated by CN 4 (trochlear n.)

A

trochlea and dorsal oblique m.

35
Q

T/F: extorsion (CN 4 damage) is most noticeable in animals with non-round pupils

A

TRUE

36
Q

what are the three branches of CN 5 (trigeminal n.)

A

ophthalmic
maxillary
mandibular

37
Q

give what the ophthalmic nerve passes through and innervates

A

orbital fissure
medial orbit/canthus, eyeball, nasal mucosa, frontal sinus

38
Q

if the ophthalmic n. is damaged what happens

A

no closure of the eye when the medial canthus is touched

39
Q

give what the maxillary nerve passes through and innervates

A

round foramen
lateral orbit/canthus, nasal mucosa, hard/soft palates, skin of rostral face, upper lip and teeth

40
Q

if the maxillary n. is damaged what happens

A

no response when the lateral canthus or upper lip/whiskers are touched

41
Q

give what the mandibular nerve passes through and innervates

A

oval foramen
muscles of mastication (temporalis, masseter, buccal, pterygoid), rostral 2/3rds of tongue, lower lip and teeth

42
Q

if there is a bilateral lesion to the mandibular n. what happens

A

dropped jaw

43
Q

if there is a unilateral lesion to the mandibular n. what happens

A

ipsilateral m. atrophy

44
Q

the upper teeth are innervated by

A

maxillary n. and infraorbital n.

45
Q

the lower teeth are innervated by

A

the inferior aveolar and mental n. branches of the mandibular n.

46
Q

what does CN 6 (abducens) innervate

A

lateral rectus m.
retractor bulbi m.

47
Q

if the CN 6 (abducens) nerve is damaged what happens

A

medial strabisimus

48
Q

what does CN 7 (facial) nerve pass-through

A

the middle and inner ear

49
Q

what does CN 7 (facial) nerve innervate

A

ear pinna (sensory)
facial muscles (motor)
lacrimal, nasal, and palatine glands
taste buds (rostral 2/3rds; special sensory)

50
Q

damage of the facial n. results in

A

loss of menace response
facial paralysis

51
Q

T/F: CN8 (vestibulocochlear n.) never leaves the skull

A

TRUE

52
Q

what are common vestibular disease signs

A
  1. head tilt
  2. nystagmus
  3. ataxia
53
Q

what is temporohyoid osteoarthropathy

A

disease of the articulation between temporal bone and hyoid apparatus in horses

pressure of swallowing can cause fractures to the temporal bone

affects CN 7 and 8

54
Q

what does CN 9 (glossopharyngeal) nerve innervate

A

salivary glands
muscles of pharynx
taste (1/3rd caudal)
sensory to caudal tongue

55
Q

what 3 nerves pass through the tympano-occipital fissure

A

CN 9, 10, and 11

56
Q

what does CN 10 (vagus n.) innervate

A

taste buds on epiglottis
mm. of larynx, pharynx, esophagus
viscera

57
Q

what nerves can be tested via the gag reflex

A

CN 9 and 10

58
Q

What muscles does the CN 11 (accessory nerve) innervate

A

trapezius
cleidocephalicus
sternocephalicus
omotransversarius

59
Q

what is cribbing

A

hypertrophy of sternocephalicus in horses

60
Q

what does CN 12 (hypoglossal n.) innervate

A

muscles of the tongue

61
Q

what is guttural pouch disease and what nerves may we be worried about

A

bacterial/fungal infection of the auditory tube expansion

CN 9, 10, 11, and 12