1. The Cranial Nerves: A Review Dr. Ann Gathers Department of Biological Sciences The University of Tennessee at Martin Health Science Teacher Education Symposium Nashville, Tennessee October 1-2, 2007

3. Athletes and Cranial Nerves Contact sports have the highest incidence of nerve injuries. In the US, approximately 1/3 of diagnosed nerve injuries were related to football trauma. Others included wrestling, weight-lifting, and baseball and softball (regional differences)

4. 12 Pairs of Peripheral Nerves Originate in or near the brain Sensory, Motor, and Mixed Voluntary, Involuntary, and Mixed

5. VENTRAL VIEW Olfactory (I) Optic (II) Oculomotor (III) Trochlear (IV) Trigeminal (V) Abducens (VI) Facial (VII) Spinal Accessory (XI) Hypoglossal (XII) Vagus (X) Glosso- pharyngeal (IX) Auditory (VIII)

6. Olfactory Optic Oculomotor Trochlear Trigeminal Abducens Facial Auditory Vagus & Glossopharyngeal

7. Spinal AccessoryHypoglossal

8. Oh Olfactory (I) OnceOptic (II) One Oculomotor (III) Takes Trochlear (IV) TheTrigeminal (V) AnatomyAbducens (VI) FinalFacial (VII) VeryVestibulocochlear (VIII) GoodGlossopharyngeal (IX) VacationsVagus (X) Seem Spinal accessory (XI) HeavenlyHypoglossal (XII)

9. Functions

10. Olfactory (I) Provides sense of smell Damage causes impaired sense of smell

11. Optic (II) Provides vision Damage causes blindness in visual field Optic (II)

12. Oculomotor (III) Some eye movement, opening of eyelid (innervates all extraocular muscles except lateral rectus & superior oblique) Constriction of pupil (parasympathetic) Focusing Damage: drooping eyelid (ptosis), dilated pupil, double vision (diplopia), difficulty focusing & inability to move eye in certain directions

13. Trochlear (IV) Provides eye movement Damage causes double vision (diplopia) & inability to rotate eye downward and outward

14. Trigeminal (V)

15. Main sensory nerve to face (touch, pain and temperature) and muscles of mastication Damage produces loss of sensation & impaired chewing Three Branches: 1.Opthalmic 2.Maxillary 3.Mandibular

16. Abducens (VI) Provides eye movement (lateral rectus) Damage results in inability to rotate eye laterally & at rest eye rotates medially (strabismus = cross-eyed)

17. Facial (VII) Facial expressions Taste on anterior 2/3’s of tongue, Salivary glands and tear, nasal & palatine glands Damage: sagging facial muscles (ptosis and corner of mouth droops) and disturbed taste (no sweet & salty sensations) i.e. Unilateral sagging facial muscles Bell’s Palsy

18. Auditory/ Vestibulocochlear (VIII) Provides hearing & sense of balance Damage produces deafness, dizziness, nausea, loss of balance & nystagmus

19. Glossopharyngeal (IX) Provides control over swallowing, salivation (parotid), gagging, sensations from posterior 1/3 of tongue, control of BP and respiration (receptors in carotid) Damage results in loss of bitter & sour taste & impaired swallowing (dysphagia)

20. Vagus (X)

21. Provides swallowing, speech, regulation of viscera (somatic and visceral) Damage causes hoarseness or loss of voice, impaired swallowing (dysphagia) i.e. Neurocardiogenic Syncope relatively new diagnosis fainting spells

22. Spinal Accessory (XI) Swallowing, head, neck & shoulder movement Damage: impaired head, neck & shoulder movement, head turns towards injured side

23. Hypoglossal (XII)

24. Tongue movements of speech, food manipulation & swallowing Damage: inability to protrude tongue if bilateral damage deviation towards injured side & ipsilateral atrophy if unilateral damage i.e. Dysarthria poor articulation

25. Thank You