Overview Snapshot A 28-year-old male presents with muscle weakness of the face that has progressively worsened over the course of a few hours. In addition, the patient reports sensitivity to sound and some loss in taste sensation. On physical exam, this muscle weakness involves both the upper and lower face. (Bell's palsy) Overview CNNameTypeFunctionCranial ExitNotesIOlfactorySensoryOlfactionCribiform plateOnly CN without thalamic relay to cortexIIOpticVisionOptic canal-IIIOculomotorMotorEye movement- SR, IR, MR, IOPupillary constrictionAccommodationEyelid opening- levator palpebraeSuperior orbital fissureCenter contains output to ocular muscles which is affected primarily 1st by vascular diseasePeriphery contains parasympathetic output which is affected 1st by compressionIVTrochlearEye movement- SO-VTrigeminalMotorSensoryMastication (V3)Facial sensation- opthalmic (V1), maxillary (V2), mandibular (V3) divisionsV1 - superior orbital fissureV2 - foramen rotundumV3 - foramen ovaleVIAbducensMotorEye movement- LRSuperior orbital fissureVIIFacialMotorSensoryFacial movementTaste from anterior 2/3 of tongueLacrimationSalivation- submandibular, sublingual glandsEyelid closing- orbicularis oculiStapedius- dampens excessive soundInternal auditory meatusVisceral sensation recieved by nucleus solitariusVIIIVestibulocochlearSensoryHearingBalance-IXGlossopharyngealMotorSensoryTaste from posterior 1/3 of tongueSwallowingSalivation- parotid glandMonitoring carotid body and sinus chemo- and baroreceptorsStylopharngeus- elevates pharynx, larynxJugular foramenMotor output orginates in nucleus ambiguusVisceral sensation recieved by nucleus solitariusXVagusTaste from epiglotic regionSwallowingPalate elevationMidline uvulaTalkingCoughingThoracoabdominal visceraMonitoring aortic arch chemo- and baroreceptorsMotor output orginates in nucleus ambiguusVisceral sensation recieved by nucleus solitariusParasympathetic fibers to heart, lungs, and upper GI orginates from dorsal motor nucleusGives recurrent laryngeal nerve which innervates all laryngeal muscles except cricothyroidXIAccessoryMotorHead turning and shoulder shrugging- SCM, trapeziusMotor output orginates in nucleus ambiguusXIIHypoglossalTongue movementHypoglossal canal