1. Cranial Nerves: I & II I. Olfactory -- sensory (smell)
nerves embedded in nasal mucosa
enter cranial cavity through olfactory foramina in cribriform plate (ethmoid bone)
synapse with other neurons in olfactory bulb impulse continues through olfactory tract
II. Optic -- sensory (sight)
nerves extend from retina
enter cranial cavity through optic foramina (sphenoid bone)
medial fibers cross at optic chiasma (sits in chiasmatic groove of sphenoid bone)
fibers continue as optic tracts
Illustration

2. Olfactory Nerve (I) – contain the sensory nerves of smell

4. Optic Nerve (II) – sensory nerve of vision

5. Visual Fields of the Eyes
Fig , p. 584

6. Cranial Nerves: III & IV
III. Oculomotor – motor
extrinsic muscles of eye except lateral rectus and superior oblique (eye movement)
intrinsic smooth muscle of iris (constriction in response to brightness) and lens (controls shape for focusing)
IV. Trochlear – motor
superior oblique muscle of eye
Illustration

7. Oculomotor Nerve (III) – “eye mover” innervates muscles that supply the eyeball

9. Trochlear Nerve (IV) – means “pulley” it innervates an extrinsic eye muscle that loops through a pulley-shaped ligament

10. Cranial Nerves: V
V. Trigeminal – mixed; largest cranial nerve, major sensory nerve serving face (skin, mucosae of mouth, surface of eyes), also important motor nerve (chewing)
mandibular division – motor to chewing muscles; sensory from anterior tongue and lower teeth
mandibular division exits/enters through foramen ovale
ophthalmic and maxillary divisions -- sensory
ophthalmic division from area around eye and forehead enters through superior orbital fissure
maxillary division from area around nose, cheeks, upper jaw enters through foramen rotundum
Illustration

11. Trigeminal Nerve (V) – supplies sensory information to the face and chewing muscles

12. Cranial Nerves: VI & VII
VI. Abducens – motor
lateral rectus muscle of eye
enters/exits cranial cavity through superior orbital fissure
VII. Facial – mixed
sensory from taste buds on tongue
motor (ANS) to salivary and lacrimal glands
motor (somatic) to muscles of facial expression
enters/exits through stylomastoid foramen
Illustration

13. Abducens (VI) – controls the extrinsic eye muscles that abduct (turn it laterally) the eyeball

14. Facial Nerve (VII) – a large nerve that innervates muscles of facial expression

15. Cranial Nerves: VIII & IX
VIII.Vestibulocochlear – sensory
hearing and balance from inner ear
enters through internal acoustic meatus
IX. Glossopharyngeal -- mixed
motor to pharyngeal muscles and salivary glands
sensory from taste buds
exits/enters through jugular foramen (border of temporal and occipital bones)
Illustration

16. Vestibulococlear Nerve (VIII) – two branches one for hearing, one for balance

17. Glossopharangeal (IX) – name means “tongue and pharynx” innervates the tongue and pharynx

18. Cranial Nerves: X X. Vagus -- mixed
motor (somatic) to pharynx and larynx for swallowing and speaking
motor (ANS: parasympathetic) innervation to heart, lungs and abdominal viscera
sensory info from thoracic and abdominal viscera
exits/enters through jugular foramen (border of temporal and occipital bones)
parasympathetic innervation to
heart --> decreases heart rate [HR]
upper GI tract (stomach, small intestines) --> increases activity
Illustration

19. Vagus (X) – name means “wanderer”
only cranial nerve to extend beyond the head

20. Cranial Nerves: XI & XII
XI. Accessory -- motor
muscles of neck
enters/exits through jugular foramen (border of temporal and occipital bones)
XII. Hypoglossal – motor
muscles of tongue (chewing, swallowing and speech)
enters/exits through hypoglossal canal (superior to occipital condyles of occipital bone)
parasympathetic innervation to
heart --> decreases heart rate [HR]
upper GI tract (stomach, small intestines) --> increases activity
Illustration

21. Accessory Nerve (XI) – joins to help the vagus nerve, innervates neck musculature

22. Hypoglossal (XII) – innervates some tongue- moving muscles

24. Cranial Nerves: I - XII
Fig. 13.4, p. 484