Cranial Nerves

  1. Cranial Nerves Carrying sympathetics
    • Cranial nerves III, VII, IX, X
    • Ciliary: CN III
    • Pterygopalantine: CNVII lacrimal gland/tears
    • Otic: CN IX parotid gland
    • Submandibular: CNVII innervation of submandibular and sublingual glands
  2. Olfactory Nerve [I]
    • Test: smell coffee or soap
    • Injury: patient can't smell
    • Traverses cribiform plate and can be damaged in head trauma
    • Tumors can compress olfactory bulb resulting in ipsilateral anosmia
  3. Optic Nerve [II]
    • Emerges from ganglion cells of retina, nerve ends in optic chiasm, becomes optic tract
    • Testing: Ophthalmoscope
    • Injury: blindness, abnormal pupillary light reflex
    • Marcus Gunn pupil: if light is shown into unaffected eye, both pupils constrict, when light is shown into affected eye, both eyes appear to dilate
  4. Oculomotor Nerve [III]
    • Somatic component: CNIII nuclei in midbrain
    • Visceral component: Nucleus of Edinger Westphal
    • Somatic joins visceral at junction of midbrain and pons, traverses cavernous sinus
    • Innervates 4/6 muscles that control eye movement
    • Controls levator palpebrae muscle to lift upper eyelid
    • Visceral motor nerve controls constriction of pupil (ciliary and constrictor pupillae muscles)
    • Testing: H pattern
    • Injury: ptosis (drooping of eye) if levator palpebrae is damaged
    • partial ptosis (horner syndrome) if superior toursal muscle damaged
  5. Trochlear Nerve [IV]
    • Somatic Motor
    • Innervates 1/6 muscles that controls eye muscles (superior oblique)
    • Causes eye to rotate inward, and move both down and laterally
    • (inferior oblique externally rotates eyes)
    • Testing: Look in and down
    • Injury: diplopia (double vision, patient tilts head towards unaffected side)
  6. Trigeminal Nerve [V]
    • General Sensory: arising from CN V nuclei in pontine area
    • Branchial Motor: arises form motor nucleus from CN V
    • Major trigeminal ganglion
    • V1- ophthalmic - transmits all pain, temp, proprioceptive information from eye, cornea, forehead, frontal and ethmoid sinses
    • V2- maxillary - transmits "..." from maxilla, nasal cavity, palate, nasopharynx, meningies of anterior and middle cranial fossa, exits via foramen rotundum
    • V3- mandibular - transmits "..." from buccal region (mucous membranes of mouth), side of head and scalp, lower jaw, teeth, anterior 2/3rds of tongue, exits via foramen ovale
  7. Branches of V1
    • Lacrimal
    • Frontal
    • Nasociliary
    • Meningeal
  8. Branches of V2
    • Zygomatic
    • Infraorbital
    • Pterygopalatine
    • Meningeal
  9. Branches of V3
    • Buccal
    • Auriculotemporal - hugs middle meningeal artery
    • Lingual - Sensory ant 2/3rds of tongue
    • Meningeal
    • Inferior Alveolar

    Branchial Motor component branches: medial pterygoid, masseteric, deep temporal, lateral pterygoid, nerve to mylohyoid, nerve to anterior belly of digastric
  10. Trigeminal Nerve Branchial motor component
    • Exits skull via foramen ovale with V3
    • Runs in mandibular nerve
    • Casts of tensor palatini and tensor tympani
    • Medial pterygoid continues to medial pterygoid muscle
    • Masseteric nerve branches off of mandibular nerve to innervate masseter
    • 2-3 branches of mandibular nerve run ot deep surface of temporalis muscle
    • Lower motor neuron injury results in paralysis of muscles of mastication
Card Set
Cranial Nerves