Cranial nerves.

Transcription

1 Cranial nerves

2 Key Points of Learning Name Components Passing through Peripheral distribution Central connection Function

3 Cranial nerves Ⅰ olfactory Ⅱ optic Ⅲ occulomotor Ⅳ trochlear Ⅴ trigeminal Ⅵ abducens Ⅶ facial Ⅷ vestibulocochlear Ⅸ glossophryngeal Ⅹ vagus Ⅺ accessory Ⅻ hypoglossal

4 Cranial nerves: connect with brain

5 Openings and fissures on base of skull for CN

6 CRANIAL NERVE General somatic motor (GSM) General visceral motor (GVM) Special visceral motor (SVM) General somatic sensory (GSS) Special somatic sensory (SSS) General visceral sensory (GVS) Special visceral sensory (SVS) Every pair of CN has not all of the above components.

7 CRANIAL NERVE

8 Pure sensory CN olfactory n. optic n. vestibulocochlear n.

9 Olfactory nerve CN I Pure sensory (SVS) --smell Olfactory bulb of telencephalon Leaves cranial cavity through foramina in cribriform plate Distributes to mucosa of superior part of lateral and septal walls of nasal cavity.

10 pure sensory (SSS)-- sight Connects with optic chiasma of diancephlon. Leaves cranial cavity through optic canal. Distributes to retina of eyeball optic n.(Ⅱ)

11 optic nerve, chiasma, optic tract

12 vestibulocochlear n. conveys impulses from inner ear sense of position terminates in vestibular N sense of hearing in cochlear N

13 Pure sensory (SSS) Internal acoustic meatus internal ear Vestibular nerve is responsible for equilibrium Cochlear nerve is responsible for hearing

14 Pure motor CN oculomotor n. trochlear n. abducens n. accessory n. hypoglossal nerve

15 oculomotor n. trochlear n. abducens n. Oculomotor n.(gsm and GVM) Midbrain Superior orbital fissure Superior division--superior rectus & levator palpebrae superioris Inferior division supplies inferior & medial rectus, & inferior oblique. GVM fibers parasympathetic, supply ciliary muscle and sphincter pupillae. Trochlear N Pure motor (GSM) ; midbrain ; Superior orbital fissure ; Superior oblique m Abducens N Pure motor (GSM) ; Pons ; Superior orbital fissure Lateral rectus m

16

17 Two roots Pure motor Medulla & spinal cord Jugular foramen Cranial root--joins X Spinal root-- sternocleidomastoid & trapezius accessory n.

18 Hypoglossal nerve Pure motor (GSM) Medulla Hypoglossal canal extrinsic and intrinsic muscles of tongue.

19 Mixed CN trigeminal n. facial n. glossopharyngeal n. vagus n.

20 Trigeminal nerve V pons Has three divisions: ophthalmic, maxillary, and mandibular nerve Has both sensory and motor components. It is the main sensory nerve for head and face. Its motor nerve innervates the muscles of mastication, etc.

21 Ophthalmic Superior orbital fissure into orbital cavity Maxillary-foramen rotundum into pteygopalatine Mandibular foramen ovale

22 Trigeminal nerve ophthalmic N superior orbital fissure Lacrimal nerve to lacrimal gland. Frontal nerve to forehead Nasociliary nerve to eyeball, part of nasal cavity, and skin of dorsum of nose from root to top.

23 Trigeminal nerve maxillary N foramen rotundum pterygopalatine fossa inferior orbital fissure, sulcus, canal and foramen to part of nasal cavity, maxilla, upper teeth, and skin between eye and mouth

24 Mandibular n. Lingual nerve to anterior 2/3 of tongue Inferior alveolar nerve to mandible, lower teeth, and chin Buccal nerve to cheek Auriculotemporal nerve to parotid gland and temporal region SVM fibers supply muscles of mastication, tensor veli palatini, and tensor tempani, etc.

25 tensor tympani M anterior belly of digastric M

26 Sensory fibers of CN V

27 Facial nerve in the temporal bone and main branches and distribution Mixed (SVM, GVM, SVS) Pons internal acoustic meatus canal of facial nerve stylomastoid foramen parotid gland SVM fibers supply muscles of facial expression & stapedius GVM fibers synapse in pterygo-palatine ganglion to supply lacrimal gland; in submandibular ganglion submandibular & sublingual gland SVS fibers receive taste from anterior 2/3 of tongue

28 facial n in the internal auditory meatus Facial nerve

29 facial n in the internal auditory meatus, canal, through the stylomastioid foramen

30 Facial nerve distributes to expression muscles

31 Facial nerve distributes to mucous of tongue

32 CN Ⅶ distributes to submandibular gland and sublingual gland through the submadibular ganglion

33 glossopharyngeal n. medulla jugular foramen GSS: carotid sinus and body, oropharynx, and posterior 1/3 of tongue SVS: receive taste from posterior 1/3 of tongue SVM: stylopharyngeus GVM: synapse in otic ganglion to supply the parotid gland

34 glossopharyngeal n. To carotid body (chemoreceptors) carotid sinus (baroreceptors ) To pharyngeal muscle, parotid salivary gland

35 to tongue general somatic and special taste sensory(posterior third)

36 The vagus nerve in the neck, thorax, and abdomen Mixed; medulla; jugular foramen; carotid sheath, on the side of mediastinum, esophgeal plexus, esophgeal hiatus anterior and posterior vagal trunks

37 The afferent fibers of vagus n. GSS in tympanic membrane, external autitory meatus, and part of the concha of the external ear. GVS are distributed widely throughout the mucous membrane of the respiratory, gastrointestinal system and internal layer of the cardiovascular. chemoreceptors in aortic bodies and baroreptors in the aortic arch

38 Parasympathetic fibers in the vagus nerve the dorsal motor nucleus of vagus. They are distributed widely throughout the respiratory, gastrointestinal system and cardiovascular. GVM

39 to the muscles of larynx and pharynx through the superior laryngeal nerves and the recurrent nerves SVM

40 SUMMARIZE Nerves of eye Nerves of tongue nerves of pharynx