The Cranial Nerves: A Review

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

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

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

Hypoglossal Spinal Accessory

Oh Olfactory (I) Once Optic (II) One Oculomotor (III) Takes Trochlear (IV) The Trigeminal (V) Anatomy Abducens (VI) Final Facial (VII) Very Vestibulocochlear (VIII) Good Glossopharyngeal (IX) Vacations Vagus (X) Seem Spinal accessory (XI) Heavenly Hypoglossal (XII)

Functions

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

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

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

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

Trigeminal (V)

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

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

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

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

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)

Vagus (X)

Vagus (X) 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

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

Hypoglossal (XII)

Hypoglossal (XII) 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

Activity -within your assigned groups create a pneumonic to help you remember the cranial nerves and their order. It can be funny or serious. Create a brochure with your pneumonic and present it to the class. Individually research a diagram of the cranial nerves using phone/ipad. Draw and label the diagram and add it to your notes. The diagram will be checked and graded.

Thank You