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Compare and Contrast cranial nerves to spinal nerves
Know which cranial nerves are central and which are peripheral
Know the 4 functions of all cranial nerves together
Draw, interpret, and analyze the corticobrainstem tracts
Explain the process of olfaction (receptors, CN I, cortical areas)
Explain taste (receptors, CN VII & IX, solitary n.)
Explain vision (visual field, anatomy & receptors, CN II, visual pathway)
Explain coordination of eye movements (III, IV, VI efferents)
Explain hearing (anatomy & receptors, CN VIII, auditory pathway)
Explain sensory and motor control of face (CN V & VII)
Explain swallowing & speaking (CN V, VII, IX, X efferents)
Explain head control (CN XII efferents)
Explain parasympathetic control of viscera (CN X)
Describe or draw the auditory, visual, and pupillary pathways
Special Senses
Motor (and somatosensory)
Autonomic
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Cranial Nerves
Spinal Nerves
• Special senses
• Vary in
components
(S, M, B)
• From specialized
nuclei in BS
• Parasympathetic
component
• Somatosensory
• Somatomotor
• Ganglia for
afferents
outside of CNS
• Reflexes
• Sympathetic
components
*
• All have both
(B)
• From gray
laminae in SC
* What are cranial nerves?
* 4 functions
* Motor innervation to muscles of face, eyes,
lips, tongue, jaw, and throat
* Somatosensory information from face and
jaw (touch, vibration, proprioception, pain,
etc)
* Special senses – vision, hearing, taste, smell,
vestibular
* Parasympathetic regulation
*
* Draw the corticobrainstem tracts!!
* Refer to this drawing during the rest of the
cranial nerves lectures!
* Corticobrainstem = corticonuclear =
corticobulbar
*
* Key Structures:
* Chemoreceptors
* Cranial Nerve I
(Olfactory bulb and
tract)
* Olfactory Cortex
* Key Points:
*
*
*
* Dysfunctions called
–osmia (ex: anosmia)
*
* Key Structures:
* Chemoreceptors
* CN VII & IX (facial & glossopharyngeal)
* Solitary Nucleus
* VPM, Gustatory Cortex
* Key Points:
*
*
*
*
* Peripheral vision is only one eye
* Blind spot is location of
optic nerve in retina
* Image is flipped – peripheral vision is
located in medial retina
* Test your peripheral vision!
* Find the edge of vision on your R,
first with your R eye, then only
with your left.
* Find your blind spot!
* Close your L eye. Find your R blind
spot with a finger.
*
* Photoreceptors
* Located in the retina
* Rods – black and white
* Cones – 3 pigmented types to detect
colors
* Cornea  Lens  Retina  Optic n.
* Fovea:
*
* Refraction of light
*
* Visual
* Carries information from retina
* Goes to LGB
* Then to hypothalamus, midbrain, primary
visual cortex
* Pupillary
* Using visual information in midbrain…
* Goes to EW, through oculomotor nerve to
constrictor muscles
*
* CN III, IV, VI
* Nuclei in midbrain & pons
* Medial Longitudinal Fasciculus
*
*
* 4 Rectus muscles, 2 Oblique muscles,
1 eyelid muscle
* Movements are normally coordinated
*
* Sound wave  tympanic membrane  3 ear bones
(malleus, incus, stapes)  cochlea  hair cells
(mechanoreceptors)  spiral ganglia  cochlear nerve
* http://www.healthline.com/vpvideo/hearing-animation
*
* CN VII (facial)
* 2 halves of facial
nucleus
* Upper
* Lower
* CN V
* muscles of mastication
*
* CN V (trigeminal)
* Ophthalmic (V1) S
* Maxillary (V2) S
* Mandibular (V3) B
* Trigeminal nuclei
* Mesencephalic
* Sensory, Motor
* Spinal
*
* Salivation  CN IX, parotid gland
* Somatosensation of posterior tongue & throat
* CN IX  Solitary n.
* Swallowing
* Nucleus Ambiguus, Solitary, Dorsal Motor of X 
combination of CNs IX, X, XII
*
* Motor control of larynx & soft palate
* Corticonuclear tract  Nucleus Ambiguus  CN X
* Motor control of tongue
* Corticonuclear tract  Hypoglossal nucleus  CN
XII
* Motor control of jaws
* Corticonuclear tract  Trigeminal motor nucleus 
CN V
* Motor control of lips
* Corticonuclear tract  Facial nucleus  CN VII
*
*
1. Smell: use smelling salts or other substances to test sense of
smell (A-1)
2. Pupillary reflex: direct & consensual responses (A-2, E-3)
3. Eye coordination: test for eye position & nystagmus (E-3,4,6)
5. Sensation of face: Touch, pain, temp (A-5)
7. Blink reflex: Test blinking (A-5, E-7)
Face muscles: Check facial expressions (E-7)
8. Test balance & hearing
9. Gag reflex: (A-9, E-10)
11. MMT trapezius & SCM (E-11)
12. Tongue: check for atrophy (E-12)
Pages 351-353 LE
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