1 - 12 Cranial Nerve Anatomy - PowerPoint Presentation

Slide1

1

-

12

Cranial Nerve Anatomy

Dr. Peterson

1Cranial Nerve I: Olfactory NerveThe 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

2Cranial Nerve II: Optic NerveThe 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 swellingRaised disc of the retina at the point of entry of the optic nerve is called the optic disc.

3Cranial Nerve III, IV, VI: Oculomotor, Trochlear & Abducens NervesThe 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 46

Brain AnatomyCN3

CN4CN6

V1 V2 V35Cranial Nerve V: Trigeminal NerveThe 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

7Cranial Nerve VII: Facial NerveThe 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)

Vertigo – spinning sensationPresbyacusis – age-relatedhearing loss 8Cranial Nerve VIII: Vestibulocochlear NerveThe 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).

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.!9Cranial Nerve IX & X: Glossopharyngeal and Vagus NervesDysarthria – difficulty with speech10

11Cranial Nerve XI: Spinal Accessory NerveFibers 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)Spinal accessory nerve syndrome – weakness/atrophy of upper trap & SCM

12Cranial Nerve XII: Hypoglossal NerveThe 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 Creditshttp://www.med.umich.edu/lrc/coursepages/m1/anatomy2010/html/modules/CN_module/Files/cn1_a.jpghttps://classconnection.s3.amazonaws.com/720/flashcards/1137720/jpg/8481354687740630.jpghttps://12cranialnerves.files.wordpress.com/2012/04/optic_pathway-3.gifhttp://www.ophthobook.com/wp-content/uploads/2007/12/no-brainstem.jpghttp://www.aafp.org/afp/2000/0115/afp20000115p427-f3.jpghttp://upload.wikimedia.org/wikipedia/commons/3/36/Gray768.pnghttp://becuo.com/vestibulocochlear-nervehttp://upload.wikimedia.org/wikipedia/commons/thumb/1/18/Brain_human_normal_inferior_view_with_labels_en-2.svg/250px-Brain_human_normal_inferior_view_with_labels_en-2.svg.pnghttp://img.tfd.com/MosbyMD/thumb/accessory_nerve.jpghttp://www.edoctoronline.com/media/19/photos_70e525d5-413a-4d15-9a87-62954e148e9a.jpg