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
The Cranial Nerves The 12 pairs of cranial nerves are parts of the PNS and pass through foramina or fissures in the cranial cavity. All but one, the Accessory Nerve [XI], originate from the brain. Each developing pharyngeal arch of an embryo is associated with a developing cranial nerve: 1) 2) 3) 4) 5) First arch: Trigeminal Nerve [V3] Second arch: Facial Nerve [VII] Third arch: Glossopharyngeal Nerve [IX] Fourth arch: superior laryngeal branch of the Vagus Nerve [X] Sixth arch: recurrent laryngeal branch of the Vagus Nerve [X] Names and Locations: # I Nerve Olfactory II III IV V Optic Oculomotor Trochlear Trigeminal VI VII VIII Abducent Facial Vestibulocochle ar Glossopharynge al Vagus Accessory Hypoglossal IX X XI XII Exit from Skull Cribiform plate of ethmoid Optic canal Superior orbital fissure Superior orbital fissure Superior orbital fissure [V1], foramen rotundum [V2], foramen ovale [V3] Superior orbital fissure Stylomastoid foramen Internal acoustic meatus Jugular foramen Jugular foramen Jugular foramen Hypoglossal canal Functional Components: Types of fibers and Parasympathetic components I. II. III. IV. V. VI. VII. VIII. Olfactory: SA Optic: SA Oculomotor: GSE, GVE Trochlear: GSE Trigeminal: GSA, BE Abducent: GSE Facial: GSA, SA, GVE, BE Vestibulocochlear: SA IX. X. XI. XII. Glossopharyngeal: GVA, GSA, SA, GVE, BE Vagus Nerve: GSA, GVA, SA, GVE, BE Accessory: GSE Hypoglossal: GSE Functions: some cranial nerves carry motor or sensory or both. # I Nerve Olfactory Function Smell II Optic Vision GSE- levator palpebrae superioris, superior and inferior rectus, medial rectus, inferior oblique muscles of eye. III IV V VI Oculomotor Trochlear Trigeminal Abducent GVE- (parasympathetic) sphincter papillae for papillary constriction, ciliary muscles of the lens for near vision Superior oblique muscle of eye GSA- sensory from face, anterior ½ scalp, mucous membranes of oral and nasal cavities and the paranasal sinuses, nasopharynx, part of ear and external auditory meatus, part of tympanic membrane, orbital contents and conjunctiva, and the dura mater of the anterior and medial cranial fossae BE- muscles of mastication, the tensor tympani, tensor veli palitini, mylohyoid, and the anterior belly of the digastric (motor is only from [V3]) Lateral rectus muscle of the eye Potential Deficits Loss of smell Blindness, visual field abnormalities, loss of papillary constriction Dilated pupils, ptosis, loss of normal papillary reflex, eye moves down and out (down inferiorly and laterally) Inability to look inferiorly when eye is adducted Loss of sensation in facial sections supplied by [V], loss of motor to mastication muscles (on same side as lesion) Inability to move eye laterally GSA- sensory from external auditory meatus and deeper parts of the auricle SA- taste for the anterior 2/3 of the tongue VII VIII Facial Vestibulocochlear GVE- (parasympathetic) stimulate secretomotor activity of the lacrimal glands, submandibular and sublingual salivary glands, and the glands in the mucous membrane of the nasal cavity, and the hard and soft palates BE- innervate the muscles of the face and scalp, stapedius, posterior belly of digastric, and the stylohyoid muscle Balance (vestibular division) and hearing (cochlear division) Paralysis of facial muscles, abnormal taste sensation from anterior 2/3 of tongue, Progressive unilateral hearing loss and ringing in the ears (tinnitis) GVA- sensory from carotid body and sinus GSA- sensory from posterior 1/3 tongue, palatine tonsils, oropharynx, and mucosa of the middle ear and eustachain tube IX Glossopharyngeal SA- taste from posterior 1/3 of the tongue GVE- (parasympathetic) secretomotor activity in the parotid gland Loss of taste to posterior ½ of tongue and sensation to the soft palate BE- stylopharyngeus muscle GSA- sensory from larynx, laryngopharynx, deeper parts of auricle, part of external auditory meatus, dura mater in the posterior cranial fossae GVA- sensory from aortic body chemoreceptors, aortic arch baroreceptors, esophagus, bronchi, lungs, heart, abdominal viscera in foregut and midgut X Vagus SA- taste around the epiglottis and pharynx GVE- (parasympathetic) stimulate smooth muscle and glands in the pharynx, larynx, thoracic viscera, abdominal viscera of foregut and midgut Soft palate deviation with deviation of the uvula to the normal side, vocal cord paralysis BE- palatoglossus (tongue), muscles of the soft palate (except tensor veli palatine), pharynx (except stylopharyngeus), and larynx XI Accessory Sternocleidomastoid and trapezius XII Hypoglossal Hyoglossus, genioglossus, styloglossus muscles, all intrinsic tongue muscles Paralysis of sternocleidomastoid and trapezius Atrophy of ipsilateral muscles of the tongue and deviation toward the affected side; speech disturbance Parasympathetic Cranial Nerve Ganglia Ganglion Ciliary Input Function [III] CN origin [III] Pterygopalatine Greater petrosal nerve [VII] Function Innervation of sphincter papillae muscle for papillary constriction and ciliary muscles for lens accommodation Innervate lacrimal Otic Submandibular Lesser petrosal nerve Chorda tympani to lingual [IX] [VII] gland, mucous glands of nasal cavity, maxillary sinus, and palate Innervate parotid gland Innervate submandibular and sublingual glands Cranial Nerve Ganglia Ganglion Trigeminal Geniculate Superior and Inferior Superior and Inferior Cranial Nerve Distribution: Input [V1], [V2], [V3] [VII], greater petrosal nerve Sensory of [IX] Sensory of [X] Cranial Nerve [V] [VII] [IX] [X]