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 CN Name Type Function Cranial Exit Notes I Olfactory Sensory Olfaction Cribiform plate Only CN without thalamic relay to cortex II Optic Vision Optic canal - III Oculomotor Motor Eye movement SR, IR, MR, IO Pupillary constriction Accommodation Eyelid opening levator palpebrae Superior orbital fissure Center contains output to ocular muscles which is affected primarily 1st by vascular disease Periphery contains parasympathetic output which is affected 1st by compression IV Trochlear Eye movement SO - V Trigeminal Motor Sensory Mastication (V3) Facial sensation opthalmic (V1), maxillary (V2), mandibular (V3) divisions V1 - superior orbital fissure V2 - foramen rotundum V3 - foramen ovale VI Abducens Motor Eye movement LR Superior orbital fissure VII Facial Motor Sensory Facial movement Taste from anterior 2/3 of tongue Lacrimation Salivation submandibular, sublingual glands Eyelid closing orbicularis oculi Stapedius dampens excessive sound Internal auditory meatus Visceral sensation recieved by nucleus solitarius VIII Vestibulocochlear Sensory Hearing Balance - IX Glossopharyngeal Motor Sensory Taste from posterior 1/3 of tongue Swallowing Salivation parotid gland Monitoring carotid body and sinus chemo- and baroreceptors Stylopharngeus elevates pharynx, larynx Jugular foramen Motor output orginates in nucleus ambiguus Visceral sensation recieved by nucleus solitarius X Vagus Taste from epiglotic region Swallowing Palate elevation Midline uvula Talking Coughing Thoracoabdominal viscera Monitoring aortic arch chemo- and baroreceptors Motor output orginates in nucleus ambiguus Visceral sensation recieved by nucleus solitarius Parasympathetic fibers to heart, lungs, and upper GI orginates from dorsal motor nucleus Gives recurrent laryngeal nerve which innervates all laryngeal muscles except cricothyroid XI Accessory Motor Head turning and shoulder shrugging SCM, trapezius Motor output orginates in nucleus ambiguus XII Hypoglossal Tongue movement Hypoglossal canal -