7.2 Cranial nerves Flashcards

1
Q

What are the modalities of cranial nerves?

A

General sensory: Perception of pain, temperature, & touch

Special sensory: Vision, smell, hearing, balance, & taste

Visceral sensory: Sensory input from viscera

Skeletal motor: Motor innervation to skeletal muscle

Visceral motor: Motor innervation to smooth muscle, organs, & glands

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2
Q

Describe CN I

A

olfactory nerve

  • Sensory: olefaction
  • from olfactory receptor cells of nasal cavity
  • Pass through cribriform plate (of ethmoid bone)
  • Fibers synapse in olfactory bulbs
  • Pathway terminates in primary olfactory cortex
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3
Q

Describe CN II

A
  • Sensory: vision
  • Arise from retinas; Pass through optic canals, converge & partially cross at optic chiasma (right visual field in left cortex)
  • Optic tracts continue to thalamus (LGN);

Optic radiation run to visual cortex

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4
Q

decribe CN III

A
  • MOTOR
  • Stomatic: riasing eyelid (levator palpebrae superioris), directing eyeball (4 extrinsic eye muslces)
  • PSNS: sphincter pupillae & cilliary muscle (adjsuts pupil size)
  • exits through sueprior orbital fissue -> various muslces around/in eye
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5
Q

Describe CN IV

A
  • trochlear nerves
  • superior oblique msucle (bends around a trochlea)
  • exists throuhg superior orbital fissure
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6
Q

Describe CN VI

A
  • the abducens nerve
  • Motor: lateral rectur muscle (when they contract, eyes abduct)
  • exit through superior orbital fissure (a lot goes through that)
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7
Q

what nerves contorl different eye muscles

A

LR6SO4 and rest are 3

Lateral rectus: CN VI (abductens)

Superior oblique: CN IV (trochlear)

medial rectus, superior rectus, inferior rectus, and inferior oblique all by CN III

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8
Q

descrine CN V

A

trigeminal nerves

  • has 3 divisions: opthalamic (V1), maxillary (V2) and mandibular (V3)
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9
Q

describe the divisions of the trigeminal nerves

A
  • Ophthalamic (V1): passes throuhg superior orbital fissue, only sensory function
    • forhead area, can pick up feeling of cavity in upper tooth,
  • Maxillary (V2): passes through foramen rotundum, only sensory
  • mandicular (V3): passes through foramen ovale, sensory and motor
    • muscles of mastication and tensor tympani and tensor veli palatine (ear muscle that dampens sound)
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10
Q

Describe CN VII

A

facial nerves

  • travels through internal acoustic meatus to exit skull via stylomastoid foramina
  • motor:
    • muscles of facial expression (opens eyes + mouth very wide, ie lion/lemon face)
    • PSNS to glands (lacrimal (tear), nasal (snot), palatine, submandibular and sublingual (saliva)
  • sensory function
    • taste from anterior 2/3 of tongue
    • skin external acoustic meatus & auricle

​​

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11
Q

placement of facial nerves

A

*CN VII

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12
Q

describe CN VIII:

A

vestibulocochlear nerves (auditory nerve)

  • Sensory: hearing (cochlear division) & equilibrium balance (vestibular division)
  • afferent fibers pass from inner ear to brainstem through internal acoustic meatuses
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13
Q

Describe CN IX:

A

Glossopharyngeal nerves

  • exit through jugular foramen (goes thru tongue and pharynx)
  • Motor
    • ​​PSNS fibers to parotid gland
    • stylopharyngeus (elevates pharynx during swallowing)
  • Sensory
    • taste: posterior 1/3 tongue
    • sensory: posterior 1/3 tongue, oropharynx, tympanic membrane, middle ear, auditor tube
    • impulses from carotid chemoreceptors and barorecaptors
      • helps pick up how blood flow is going to brain

*to check it test gag reflex

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14
Q

describe CN X

A

vagus never

  • exit skull via jugular foramen
  • motor
    • PSNS innervation of heart, lungs & abdominal viscera
    • muscles of larynx and pharynx (imp for speech, issues with vagus nerve -> 1st symptom if hoarsness in voice)
  • Sensory
    • sensory form thoracic/abdominal viscera & posterior ear/external acoustic meatus
    • barorecaptors and chemoreceptors (detect changes in blood)
    • taste from posterior tongue and pharynx
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15
Q

Describe CN XI

A

spinal accessory nerves

  • Motor: trapezius and sternocleidomastoid
    • formed from ventral rootlets from C1-C5 region of spinla chord (not of brain)
      • ​exists skull @ superior aspect of spinal chord
    • rootlets pass into cranium via foramen magnum
    • accessory nerves exit skill via jugular foramina

*to test turn head against pressure

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16
Q

Describe CN XII

A

hypoglossal nerves

motor: innervate majority of tongue muscles contributing to swallowing, speech and mastication

exit skull via hypoglossal canal (hole right near tongue)

*test: stick out tounge

17
Q

Role of cranial nerves

A

CNI: Olfactory : SENSORY

CN II: Optic: SENSORY

CN III: Oculomotor : MOTOR

CN IV: Trochlear: MOTOR

CN V: Trigeminal: BOTH

CN VI: Abducens: MOTOR

CN VII: Facial: BOTH

CN VIII: Vestibulocochlear/Auditory: SENSORY

CN IX: Glossopharyngeal: BOTH

CN X: Vagus BOTH

CN XI : Spinal accessory; MOTOR

CN XII: Hypoglossal : MOTOR

oh, oh, oh to touch and feel a girls very soft hand
some say money matters, but my brother says big brains matter more

18
Q

cranian nerve innvervation of tongue: motor function

A

CNX: muscles of pharynx

CN XII: all of muslces of tongue and pharynx

19
Q

cranial nerve innervation of tongue: sensory

A

CN IX: general sensory (ability to feel tongue, ie biting it)

CN X: taste

CN iX: general sensory and taste

CN V3: general sensory

CN VII: taste

20
Q

What nerves are involved in general sensory modality (pain temp, touch)

A

CN: V, VII, IX, X

21
Q

what cranial nerves are associated with special sensory (vision, smell, hearing, balance, and taste)

A

CN: I, II, VII, VIII, IX, X

22
Q

what cranial nerves are involved in visceral sensory (input from viscera)

A

IX, X

23
Q

What cranial nerves are invovled in skeletal motor modalities (motor innervation to skeletal muscle)

A

CN; III, IV, V, VI, VII, IX, X, XI, XII

24
Q

What cranial nerves are involes in visceral motor function (motor innervation to smooke muscle, organs and glands)

A

CN III, VII, IX, X