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129 Cards in this Set
- Front
- Back
List 3 functions of cranial nerves:
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1. To provide motor/sense innervation to head/neck
2. To innervate special sense organs 3. To carry ANS fibers |
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What are the 3 sensory modalities of cranial nerves?
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1. Special sense
2. Somatic sense 3. Visceral sense |
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What information is obtained by special sensory nerves?
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-Smell (CN I)
-Vision (CN II) -Taste (CNs VII, IX, X) -Hearing/Balance (CN VIII) |
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What info is obtained by somatic sensory nerves?
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Proprioception, pain, temp, vibration, touch, from the skin and body wall.
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What info is obtained by visceral sensation?
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Info re: glands and organs in thoracic/abdominal/pelvic cavities
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What is visceral motor innervation responsible for?
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Innervation of cardiac muscle, smooth muscle, and glands.
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What is branchial motor innervation responsible for?
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Innervation of muscles derived from branchial arches
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What 4 types of muscles are branchially derived?
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-Mastication
-Face expression -Pharynx -Larynx |
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What is somatic motor innervation responsible for?
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Innervation of skeletal muscles from myotomes
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What muscles in the head are considered somatic?
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Extraocular
Tongue |
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What nerves are purely special sensory?
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I - olfactory
II - optic VIII - acoustic CAPOLO in reverse |
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What nerves are purely somatic motor?
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IV - Trochlear
VI - Abducens XII - Hypoglossal HAT |
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What cranial nerves are special sensory?
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One, Two, and 7-10
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What cranial nerves are somatic sensory?
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5, 7, 9, 10
the store and one more |
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What cranial nerves are visceral sensory?
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9 and 10
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What cranial nerves are visceral motor?
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3, 7, 9, 10
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What cranial nerves are branchial motor?
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5, 7, 9, 10, 11
the store and two more |
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What cranial nerves are somatic motor?
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3, 4, 6, 12
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Purely sensory cranial nerves:
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1, 2, 8
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CN 1 - Olfactory:
-Function -Neuron cell body locations -Skull passage -Injury -Possible cause of injury |
Function = smell
NCB = olfactory epithelium Skull hole = cribiform plate Injury = anosmia Cause = fracture of crib plate |
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CN II - optic
-Function -Neuron cell body locations -Skull passage -Injury -Possible cause of injury |
-Function = vision
NCB = back of retina -Skull passage = optic canal -Injury = anopsias -Cause = eyeball trauma |
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CN VIII - Vestibulocochlear
-Function -Neuron cell body locations -Skull passage -Injury -Possible cause of injury |
Function = hearing and balance
NCB = Cochlea (spiral ganglion) and Semicircular canals (vestibular ganglion) Skull hole = internal acoustic meatus Injury: hearing impaired or loss, tinnitus, vertigo Cause: tumor |
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Purely MOTOR nerves:
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3, 4, 6, 11, 12
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CN III - Oculomotor
-Function -Neuron cell body locations -Skull passage |
Function = eye movement
NCB: upper midbrain oculomotor nucleus Hole: superior orbital fissure |
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What is the route of the oculomotor nerve (4 points)
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1. Emerges near median plane at midbrain/pons junction
2. Passes between posterior cerebral & superior cerebellar arteries 3. Passes through cavernous sinus & Superior orbital fissure 4. Passes within common tendinous ring of rectus muscles |
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What 5 muscles does CN III innervate?
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1. Levator palpebrae
2. Superior rectus 3. Inferior rectus 4. Medial rectus 5. Inferior oblique |
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What are 3 types of CN 3 injuries?
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1. Ptosis
2. Lateral stabismus 3. Diplopia |
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what is ptosis?
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When the eyelid droops due to paralysis of levator palpebrae
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What is lateral strabismus?
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When the eye turns down and laterally due to unopposed action of superior oblique and lateral rectus
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What is diplopia?
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double vision due to lateral strabismus
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What are 2 possible causes of oculomotor nerve injuries?
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1. Cavernous sinus injury
2. Aneurysms of posterior cerebral or superior cerebellar arteries. |
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CN IV - Trochlear
-Function -Neuron cell body locations -Skull passage -Structure innervated |
Function: eye movement
NCB: lower midbrain trochlear nucleus Skull hole: superior orbital fissure Innervates Superior oblique m |
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Descrie the route of the trochlear (CN IV) nerve (3 points):
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1. Emerges from dorsal midbrain
2. Passes thru cavernous sinus and superior orbital fissure 3. Passes outside common tendinous ring from which rectus muscles originate |
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What is special about the trochlear nerve route?
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It is the only cranial nerve to emerge from the dorsal aspect of the brain.
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How is the eye impaired when CN IV is injured?
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Unable to look down when eye is adducted -> results in diplopia
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What is a possible cause of CN IV injury?
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Cavernous sinus injury
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CN VI - Abducent
-Function -Neuron cell body locations -Skull passage -Innervated structure |
Function = eye movement
NCB = pons abducent bodies Skull hole = sup. orbital fiss. Innervates lateral rectus m. |
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Describe the route of CN VI (3 points):
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1. Emerges near median plane at junction of pons/medulla
2. Passes thru cavernous sinus and superior orbital fissure 3. Passes within common tendinous ring from which rectus muscles originate |
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2 types of abducent nerve injuries:
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Medial strabismus
Diplopia |
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What is medial strabismus?
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Eye turns medially due to unopposed action of medial rectus m.
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What is diplopia again?
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double vision due to medial strabismus
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What are 2 possible causes of abducent nerve injuries?
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1. Cavernous sinus injury
2. Fracture of skull base |
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CN XI - Spinal accessory
-Function -Neuron cell body locations -Skull passage -Injury -Possible cause of injury |
Function: head/neck movement
NCB: spinal cord - anterior horn of cervical region |
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How on earth does the spinal accessory nerve enter the skull?
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Through foramen magnum; then it exits through the jugular foramen; how weird...
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hello
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hello
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what does cN XI innervate?
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-Trapezius
-Sternocleidomastoid |
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what are 2 types of injuries to the spinal accessory nerve?
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1. Weak turning head to opposite side
2. Weak shugging shoulders |
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What could cause injury to CN XI?
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Well a neck laceration; like what if you got into a knife fight, that could do it.. what else?
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So CN XI emerges from the spinal cord; what might be confused with its roots?
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CN X (vagus) also arises from cranial roots, but these are medulla roots; only CN XI arises from spinal cord roots, and it doesn't arise from the medulla at all.
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CN XII - Hypoglossal:
-Function -Neuron cell body locations -Skull passage -Injury -Possible cause of injury |
Function = swallow/suck/chew/
stick tongue out. NCB: medulla - hypoglossal nucleus Skull hole: hypoglossal canal Innervates: all tongue muscles iexcept one extrinsic Injury: unilateral lesion Cause: neck laceration |
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What is the route of the hypoglossal nerve? (2 points)
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1. Emerge from side of medulla (anterior to olives..)
2. pass through hypoglossal canal; curve forward near mandibular angle to "ansa cervicalis" to enter tongue. |
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What extrinsic tongue muscle does the hypoglossal n NOT innervate? What does innerv. it?
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Palatoglossus - CN X
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What results from a unilateral lesion of the hypoglossal nerve?
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Protruded tongue deviates to one side.
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3 divisions of CN V:
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-Ophthalmic
-Maxillary -Mandibular |
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What kind fo nerve is each division of CN V?
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Opthalmic = purely sensory
Maxillary = purely sensory Mandibular = mixed motor/sensory |
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Opthalmic CN V1:
-Function -NCB location -Skull hole -Injury -Cause of injury |
Function: senssory from skin of forehead, scalp, nasal mucous membranes.
NCB: trigeminal ganglion Skull hole: Sup orb fissure Injury: Anesthesia Cause: inflammation |
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Maxillary - CN V2
-Function -NCB location -Skull hole -Injury -Cause of injury |
Function: Sensory from skin of upper lip, cheek prominence, palate, maxillary sinus.
NCB: Trigeminal ganglion Skull hole: Forament rotundum Injury: Anesthesia and Trigeminal neuralgia Cause: inflammation |
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What is trigeminal neuralgia, and another name for it?
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Intermittent excruciating pain; aka Tic douloureux
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Mandibular - CN V3; SENSORY
-Function -NCB location -Skull hole -Injury -Cause of injury |
Function: sensory from skin of lower jaw, ant 2/3 tongue
NCB: trigeminal ganglion Skull hole: foramen ovale Injury: Anesthesia/Trigeminal neuralgia Cause: inflammation |
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Mandibular - CN V3; MOTOR
-Function -NCB location -Skull hole -Injury -Cause of injury |
Function: branchial motor - swallowing and chewing
NCB: pons - motor nucleus of V Skull hole: Foramen ovale Injury: difficulty chewing Cause: inflammation |
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8 muscles innervated by CN V3 - MOTOR:
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-Temporalis
-Medial/Lateral Pterygoids -Masseter -Tensor veli palatini -Tensor tympani -Mylohyoid -Digastric (anterior belly) |
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What cranial nerves have both sensory and motor functions?
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V, VII, IX, X
5, 7, 9, 10 (store + 1 more) |
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The facial nerve has 3 modalities of functions; what are they?
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-Somatic sensory
-Special sensory -Branchial motor |
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-What is the specific somatic sensory function of CN VII?
-What is its specific special sensory function? -What is its motor function? |
Somatic sense: skin behind ear, external acoustic meatus, tympanic membrane.
Special sense: taste from anterior 2/3 tongue & palate. Motor: facial expression |
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What is the location of CN VII's
-Sensory NCBs? -Motor NCBs? |
Sensory = geniculate ganglion
Motor = pons |
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Through what specific BONE does CN VII enter/exit the skull, and at what parts?
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TEMPORAL BONE:
Entrance: internal acoustic meatus Exit: stylomastoid foramen |
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What will injury to CN VII's somatic sensory component result in?
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Anesthesia
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What will injury to CN VII's SPECIAL sensory component result in?
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Loss of taste sensation in the tongue's anterior 2/3rds.
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What could cause injury to the special sense component of CN VII?
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Injury to the chorda tympani n.
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What are the 5 terminal branches of the facial motor nerve?
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-Temporal
-Zygomatic -Buccal -Mandibular -Cervical |
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What 4 structures are innervated by CN VII?
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-Facial expression muscles
-Stapedius -Stylohyoid -Digastric (posterior belly) |
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What innervates the digastric
-Anterior belly? -Posterior belly? |
Ant = V3 - mandibular n.
Post = CN VII |
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What are the muscles of facial expression?
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-Orbicularis oculi/oris
-Platysma -Buccinator -Frontalis -Occipitalis |
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What does an injury to the CN VII result in, and what could cause it?
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Bell's palsy - caused by injury in region of parotid gland.
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What are 4 symptoms of bell's palsy?
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1. Facial muscle paralysis
2. Inability to close eyes (paralyzed orbicularis oculi) 3. Angle of mouth droops 4. Inability to wrinkle forehead |
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What type of lesion of CN VII will cause inability to wrinkle forehead, and why?
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Only PERIPHERAL - b/c frontalis is bilaterally innervated.
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Glossopharyngeal CN IX has four functional modalities; what are they?
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1. Somatic sensory
2. Visceral sensory 3. Special sensory 4. Branchial motor |
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CN IX - somatic sensory from 7 places:
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PSTPAMM
-Posterior 1/3rd tongue -Tonsils -Soft palate -Pharynx -Auditory tube -Middle ear -Mastoid air cells |
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Where are CN IX's NCBs
-for sensory components? -for motor components? |
Sensory: Superior ganglion of IX
Motor: nucleus ambiguus in medulla |
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What path does the glossopharyngeal n. take to get out of the brain?
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Runs along the temporal bone and occipital bone to exit via the jugular foramen.
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What will injury to CN IX do to its somatic sensory abilities?
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Cause dysphagia (difficulty swallowing) and/or dysarthria (speech difficulty)
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What is a possible cause of injury to the glossopharyngeal nerve?
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Neck laceration
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What is the 2 functions of CN IX's visceral sensory ability?
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1. Detectn of O2 tension in the carotid BODY via chemoreceptors
2. Detectn of blood pressure in carotid SINUS via baroreceptors |
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How will injury to visceral sensation of glossopharygneal n. manifest?
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As changes in blood pressure
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What is the special sensory function of CN IX?
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Taste from the posterior 1/3rd of tongue.
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What is the branchial motor function of CN IX?
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Phonation - elevation of the pharynx.
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What muscle does CN IX specifically innervate?
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Stylopharyngeus
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What will injury to the motor function of CN IX result in?
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Dysphagia (difficulty swallowing) and/or dysarthria
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CN X - the Vagus nerve - has 4 functional modalities; they are?
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1. Somatic sensory
2. Visceral sensory 3. Special sensory 4. Branchial motor |
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From where does CN X receive somatic sensation? (6 places)
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PLEETME: Pharynx, larynx, external ear, external auditory canal, tympanic membrane, and meningies in posterior cranial fossa.
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Where are the somatic sensory NCB's of CN X located?
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In the superior ganglion of CN X
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Where are the special sensory NCB's of CN X located?
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Inferior ganglion of CN X
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Where are the visceral sensory NCB's of CN X located?
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Inferior ganglion of CN X
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Through what bones/hole does the vagus nerve pass thru/exit the skull?
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-Temporal/occipital bones
-Jugular foramen |
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What special sensory function does CN X have?
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Taste from the epiglottis
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What are the 3 visceral sensory functions of CN X?
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1. Sensation in muscles/mucous membranes in pharynx/larynx and thoracid/abdominal viscera
2. Chemoreceptors in AORTIC BODY adjacent to aortic arch 3. Stretch receptors in aortic arch walls |
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What is the branchial motor functino of CN X?
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Speech
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Where are the motor NCBs of CN X located?
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In the nucleus ambiguus of the medulla
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What branchial muscles are innervated by CN X? (6)
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-Soft palate skeletal muscles - EXCEPT 2!!
-Pharyngeal constrictor mm -Levator palati -Salpingopharyngeus -Palatopharyngeus -Palatoglossus |
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What are the 2 EXCEPTIONS to soft palate muscles innervated by CN X? What are they innervated by?
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Stylopharyngeus - CN IX
Tensor veli palatini - CN V3 |
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What are 3 results of injury to the branchial component of the vagus nerve?
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1. Sagging soft palate
2. Difficulty coughing, swallowing, clearing throat, etc 3. Dysphagia |
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What does the autonomic nervous system innervate?
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-Smooth muscle
-Cardiac muscle -Glands |
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What are the divisions of ANS?
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-Sympathetic
-Parasympathetic |
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What is the format of the ANS?
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1. Preganglionic NCBs in a brain nucleus OR sp. cd. gray matter.
2. Preganglionic fibers travel WITH CRANIAL NERVES. 3. Preganglionic fibers SYNPSE on postganglnic fiber's cell body in a peripheral ganglion. 4. Postganglnc fibers travel with CRANIAL NERVES 5. Postgnglnc fibers innervate target organs, they respond. |
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What cranial nerves have autonomic function?
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3, 7, 9, 10
CN III - oculomotor CN VII - facial CN IX - Glossopharyngeal CN X - Vagus |
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CN III:
-Preganglionic NCB location -Route -Postganglionic NCB location -Route -Target |
Pre NCB: Edinger westphal nuceus in upper midbrain
Pre Route: with CN III Post NCB: Ciliary ganglion (V1) Post route: w/ short ciliary n Target: Sphincter pupillae and Cilary muscles |
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Loss of CN III autonomic function results in:
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1. Myodiasis - unopposed dilation of pupils
2. Inability to read up close |
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CN VII has what 2 autonomic functions?
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-Lacrimal innervation
-Salivatory innervation |
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CN VII - lacrimal:
-Preganglionic NCB location -Route -Postganglionic NCB location -Route -Target |
Pre NCB: superior salivatory nucleus in pons
Route: thru nervous intermedius and geniculate ganglion (both CN VII); via Greater petrosal n. to Nerve of Pterygoid canal Post NCB: Pterygopalatine ganglion (attchd to V2) Post route: Via zygomaticotemporal n (v2) and lacrimal nerve (v1) Target: Lacrimal gland and mucosa of nasal cavity, nasopharynx, and palate. |
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What will injury to CN VII lacrimal function result in?
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Dry corneas
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CN VII - salivary
-Preganglionic NCB location -Route -Postganglionic NCB location -Route -Target |
Pre NCB: superior salivatory nucleus
-Pre Route: thru nervous intermedius and geniculate ganglion (both VII); via Chorda tympani to join Lingual n. (v3) -Post NCB: Submandibular ganglion (attached to v3) -Post route: already there -Target: submandibular and sublingual glands |
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Injury to salivary function of CN VII results in:
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failure to salivate at those glands.
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CN IX
-Preganglionic NCB location -Route -Postganglionic NCB location -Route -Target |
Pre NCB: inferior salivatory nucleus
Route: exit brain w/ CN IX fibers, pass thru tympanic n and lesser petrosal n. Post NCB: otic ganglion (attchd to V3) Post route: runs w/ auriculotemporal n (of V3) Target: parotid gland |
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Injury to salivary function of CN IX results in:
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failure to salivate at parotid gland.
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CN X
-Preganglionic NCB location -Route -Postganglionic NCB location -Route -Target |
Pre NCB: Dorsal motor nucleus of CN X in medulla
Route: run with CN X Post NCB: autonomic ganglia near or w/in target organ walls Target smooth muscle and glands of GI tract, pulmonary, and cardiovascular systems |
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Purely sensory nerves: (3)
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1, 2, 8
Olfactory Optic Vestibulocochlear |
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Sensory + motor nerves: (4)
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5, 7, 9, 10
Trigeminal Facial Glossopharyngeal Vagus |
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Purely motor nerves: (5)
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3, 4, 6, 11, 12
Oculomotor Trochlear Abducent Spinal accessory Hypoglossal |
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Nerves associated w/ Special Senses: (6)
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1, 2, 7, 8, 9, 10
I = olfactory = smell II = optic = vision VII = facial = taste (ant 2/3) VIII = vestibulocochlear = balance and hearing IX = glossopharyngeal = taste (post 1/3) X = vagus = taste (epiglottis) |
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Cranial nerves passing thru cavernous sinus:
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3, 4, 5 (1/2), 6
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Cranial nerves innervating extraocular muscles:
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3, 4, 6
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Cranial nerves carrying preganglionic parasympathetic fibers:
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3 (sphincter pupillae and ciliary muscles)
7 (lacrimal, submandibular and sublingual glands) 9 (parotid) 10 (smooth muscle of thorax and abdominal viscera) |
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Cranial nerves to which parasympathetic ganglia are attached:
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V1 = ophthalmic - ciliary ganglion
V2 = maxillary - pterygopalatine ganglion V3 = mandibular - otic and submandibular ganglia |
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Which cranial nerves pass thru the ethmoid bone?
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only one; olfactory CN I
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Which cranial nerves pass thru the sphenoid bone?
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2,3,4,5,6
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Which nerves pass thru what holes in the sphenoid bone?
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2 = optic canal
3, 4, V1, 6 = sup orb fissure V2 = foramen rotundum V3 = foramen ovale |
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Which cranial nerves pass thru the Temporal bone?
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7, 8, 9, 10, 11
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Which nerves pass thru what holes in the temporal bone?
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7 & 8 = internal acoustic meatus
9-11 = jugular foramen 11 = also thru foramen magnum |
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Which cranial nerves pass thru the occipital bone?
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only one; hypoglossal CN XII passes thru hypoglossal canal.
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