INTRODUCTION TO THE CRANIAL NERVES I. The 12 pairs of cranial nerves arise from the inferior aspect of the brain and are part of the PNS (peripheral nervous system). In general, the cranial nerves control functions of the head & neck and some autonomic functions in the thorax and abdomen. CN# CN I CN II CN III Name olfactory nerve optic nerve oculomotor nerve Basic Function -special sense of smell [SS] -special sense of sight [SS] -controls 5 extraocular muscles (SE, SA) -controls pupillary constriction & focusing (PARA) [SE, SA, & VE-Para/Pre] controls 1 eye muscle [SE, SA] has 3 divisions general sensation to upper face [SA] general sensation to mid face, upper teeth, nasal cavity, palate, & upper nasopharynx [SA] -general sensation to lower face, lower teeth, & anterior 2/3rd of tongue; [SA] -controls muscles of mastication & a few other related muscles [BM] controls 1 eye muscle [SE, SA]

CN IV CN V V1 V2 V3

trochlear nerve trigeminal nerve opthalmic division maxillary division mandibular division

CN VI ** **just like CN IV CN VII

abducens nerve

facial nerve

-controls muscles of facial expression (BM) -special sense of taste to anterior 2/3rd tongue (SS) -controls two salivary glands (para) -controls tear glands (para) -controls mucus glands for nasal cavity, palate, & upper nasopharynx (para) -provides general sensation to a small patch of skin of outer ear (SA) [BM, SS, SA, VE-Para/Pre]

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CN VIII CN IX

vestibulocochlear nerve glossopharyngeal nerve

special sense of hearing & balance [SS] -controls 1 pharyngeal muscle (for swallowing) [BM] -special sense of taste to posterior 1/3rd tongue [SS] -general sensation to posterior 1/3rd tongue, oropharynx, eardrum, middle ear cavity [SA or VA] -monitors blood pressure & gas levels [VA] -controls mucus glands of oropharynx (PARA) -controls 1 salivary gland (PARA) -provides general sensation to a small patch of skin of outer ear (SA) gag reflex sensory arm (VA) [BM, SS, SA, VA, VE-Para/Pre]-controls muscles of the soft palate, pharynx, & larynx (for speaking & swallowing) [BM] -special sense of taste to root of tongue area [SS] -controls mucus glands of laryngopharynx & larynx (PARA) -provides general sensation to a small patch of skin of outer ear (SA) -is the the major source of VE-para/pre fibers to the organs of the thorax & abdominal organs of the foregut and midgut (PARA) -gag reflex motor arm (VA) [BM, SS, SA, VA, VE-Para/Pre]

CN X

vagus nerve

CN XI

accessory nerve (has 2 parts) spinal part controls 2 muscles of the neck and shoulder [SE, SA] SCM laterally bends & rotates neck trapezius shrugs shoulders travels with CN X (we call it XI via X fibers) and supplies most of the BM fibers found in CN X. controls muscles of the tongue [SE, SA]

cranial part CN XII hypoglossal nerve

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