Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Cranial Nerve Anatomy Dr. Peterson Cranial Nerve I: Olfactory Nerve • The axons of these cells extend through the cribriform plate of the ethmoid bone into the olfactory bulb at the anterior end of the olfactory nerve. anosmia – lack of smell Cranial Nerve II: Optic Nerve Raised disc of the retina at the point of entry of the optic nerve is called the optic disc. • The optic nerve carries visual information from the retina (cells sensitive to light) through the optic chiasm to the lateral geniculate nucleus of the thalamus and then to the extrageniculate pathways, including the visual cortex in the occipital lobe. papilledema – optic disc swelling Cranial Nerve III, IV, VI: Oculomotor, Trochlear & Abducens Nerves Brain Anatomy CN3 CN4 • The oculomotor (III) and trochlear (IV) nerves are located in the midbrain. The abducens nerves are located in the pons. All are responsible for extraocular eye movements. CN III is also responsible for pupillary constriction. strabismus – eye deviation CN6 Cranial Nerve V: Trigeminal Nerve • The trigeminal nerve (CN V) exits the brainstem at the ventrolateral pons and the 3 divisions exit foramen in the skull. CN V provides sensation to the face. Trigeminal neuralgia – severe nerve pain (neuralgia) involving 1 of 3 branches Cranial Nerve VII: Facial Nerve • The facial nerve (CN VII) exits the brain at the pontomedullary junction in a region called the cerebellopontine angle to the internal auditory meatus to the facial canal in the temporal bone. CN VII is primarily responsible for the muscles of facial expression, taste and dampening sounds. Bell’s palsy – unilateral facial weakness (CN VII palsy) Cranial Nerve VIII: Vestibulocochlear Nerve • The vestibulocochlear nerve (CN VIII) exits the brainstem at the pontomedullary and travels with facial nerve until it travels in the auditory canal to reach the cochlea spiral-shaped cavity of the inner ear and the main organ of hearing) and vestibular organs (utricle, saccule, and the three semicircular ducts of the membranous labyrinth of the inner ear). Vertigo – spinning sensation Presbyacusis – age-related hearing loss Cranial Nerve IX & X: Glossopharyngeal and Vagus Nerves Dysarthria – difficulty with speech • The glossopharyngeal (IX) exits the brainstem out from the sides of the upper medulla, just rostral (closer to the nose) to the vagus nerve (X). CN X is passes through the neck & thorax to the abdomen. CN IX is responsible for swallowing, taste & sensation to the pharynx. CN X is responsible for HR, peristalsis, sweating, speech, etc.! Cranial Nerve XI: Spinal Accessory Nerve Spinal accessory nerve syndrome – weakness/atrophy of upper trap & SCM • Fibers of the spinal accessory nerve (CN XI) originate in the upper spinal cord, form rootlets, roots, and then the nerve itself. CN XI exits the foramen magnum and supplies the upper trapezius (shoulder elevation) and SCM (neck rotation) Cranial Nerve XII: Hypoglossal Nerve • The hypoglossal nerve (CN XII) exits the brain at the medulla oblongata. CN XII is responsible for tongue manipulation responsible for speech, food manipulation and swallowing. Image Credits • http://www.med.umich.edu/lrc/coursepages/m1/anatomy2010/html/modules/CN_module/Files /cn1_a.jpg • https://classconnection.s3.amazonaws.com/720/flashcards/1137720/jpg/8481354687740630.jpg • https://12cranialnerves.files.wordpress.com/2012/04/optic_pathway-3.gif • http://www.ophthobook.com/wp-content/uploads/2007/12/no-brainstem.jpg • http://www.aafp.org/afp/2000/0115/afp20000115p427-f3.jpg • http://upload.wikimedia.org/wikipedia/commons/3/36/Gray768.png • http://becuo.com/vestibulocochlear-nerve • http://upload.wikimedia.org/wikipedia/commons/thumb/1/18/Brain_human_normal_inferior_vi ew_with_labels_en-2.svg/250px-Brain_human_normal_inferior_view_with_labels_en-2.svg.png • http://img.tfd.com/MosbyMD/thumb/accessory_nerve.jpg • http://www.edoctoronline.com/media/19/photos_70e525d5-413a-4d15-9a87-62954e148e9a.jpg