Module 4 - Cranial Nerves Flashcards
What is general somatic afferent?
sensory; pain, temperature, and mechanical stimuli in skin, muscle, joints
What is special somatic afferent?
sensory; special senses of sight, hearing, equilibrium
What is general visceral afferent?
sensory; visceral structures
What is general somatic efferent
voluntary motor control
What is special visceral afferent?
smell and taste
What is general visceral efferent?
autonomic innervation of smooth muscle
What is special visceral efferent?
same as branchial efferent - certain striated muscles muscles of the face, larynx, pharynx; identical to normal striated muscles but the neurons have distinctive location in brainstem
Damage to UMNs results in what?
spasticity
Damage to LMNs results in what?
paralysis/weakness
What is CN I?
olfactory
What is CN II?
optic nerve
If there’s damage to CN II BEFORE the optic chiasm, what would happen?
would lose one eye, but have both visual fields
If there’s damage to CN II AFTER the optic chiasm, what would happen?
both eyes probably intact, but one visual field is missing
What is CN III?
Oculomotor; visual tracking, fixation on object, pupil adjustments, elevation of eyelid
What is CN IV?
Trochlear: motor for the eye
What is CN VI?
Abducens: Motor for a few eye muscles
Where does CN V originate?
Pons
What are the three branches of CN V?
opthalmic (sensory), maxillary (sensory), mandibular (motor and sensory)
CN V provides motor innervation to what?
muscles of mastication
LMN damage to CN V results in what ?
flaccid paralysis of the ipsilateral mastication muscles; jaw deviates toward affected side; jaw protrusion affected
Bilateral UMN damage to CN V results in what?
severe effects characterized by restricted movements, swallowing and articulation difficulties
Unilateral UMN damage to CN V results in what?
mild effects - bilateral innervation
What are the four branches of CN VII?
branchial motor, visceral motor, special sensory, general sensory
What does the branchial motor of CN VII do?
voluntary control of the muscles of facial expression and some suprahyoids
What does the visceral motor branch of CN VII do?
secretion from submandibular, sublingual and lacrimal glands; mucous membranes of nasopharynx and hard and soft palates
What does the special sensory branch of CN VII do?
taste information from anterior 2/3 of tongue and hard and soft palates
What does the general sensory branch of CN VII do?
sensory information from ear
So in general: CN VII?
muscles of facial expression, sensation in front of mouth, salivary glands, taste to front of tongue
LMN damage to CN VII results in what?
sensory deficits; if just branchial motor branch, results in facial paralysis (bell’s palsy)
Unilateral LMN damage to CN VII results in what?
loss of voluntary control of lower muscles of facial expression; voluntary control of muscles of the forehead will be spared due to bilateral innervation
Bilateral LMN damage to CN VII results in what?
paralysis of all upper and lower facial muscles; pseudobulbar palsy; significant impairments in articulation, facial expression
What are the two branches of CN VIII?
auditory, vesitbular
What are the five branches of CN IX?
branchial motor, visceral motor, visceral sensory, general sensory, special sensory
What does the branchial motor of IX do?
voluntary control of stylopharyngeus (elevates larynx and pharynx during swallowing and speech)
What does the visceral motor branch of IX do?
innervates the ipsilateral parotid salivary gland.
What does the visceral sensory branch of IX do?
baroreceptors of carotid sinus and chemoreceptors of the carotid body
What does the General Sensory branch of IX do?
pain, temperature, and touch of external ear, surface of TM, walls up upper pharynx, and posterior on third of the tongue
What does the Special sensory branch of IX do?
taste from posterior 1/3 of tongue
so in general: CN IX?
stylopharyngeus (elevates larynx and pharynx), salivary, sensation in a lot of places, including upper pharynx and back of tongue, taste on back of tongue
LMN damage to CN IX
poor pharyngeal and laryngeal elevation during swallowing, loss of taste from back of tongue, absent gag reflex (possibly)
What are the five branches of CN X?
branchial motor, visceral motor, visceral sensory, general sensory, special sensory
What are the three major branches of the branchial motor branch of CN X?
pharyngeal, superior laryngeal, recurrent laryngeal
What does the pharyngeal branch of CN X do?
motor innervation to constrictors, tensor veli palatini, salpingopharyngeus, palatopharyngeus, and palatoglossus
What does the superior laryngeal branch of CN do?
exterior: motor for inferior constrictor and cricothyroid muscle;
interior: sensory for larynx
What does the recurrent laryngeal branch of CN X do?
innervate all intrinsic laryngeal muscles except cricothyroid
What does the visceral motor branch of CN X do?
innervate smooth muscle and glands of pharynx, larynx, thoracic and abdominal viscera… “rest and digest”
Unilateral LMN damage to X results in what?
hoarseness (due to paralysis of one side of larynx), difficulty swallowing, soft palate droops on the affected side and the uvula droops on the opposite side
Bilateral LMN damage to X results in what?
severe problems in voice, resonance, and swallowing.
Unilateral UMN damage to X results in what?
harsh voice, less severe effects due to bilateral innervation
What does XI do?
courses with X and provides some motor innervation to pharynx and larynx
What does CN XII do?
motor to the tongue (except palatoglossus)
unilateral LMN damage to XII does what?
ipsilateral lingual paralysis; tongue is flaccid and will atrophy; deviates to weak side
bilateral LMN damage to XII does what?
significant impairment
UMN damage to XII does what?
loss of skilled motor movements in tongue
