Chapter 13 - The peripheral nervous system and reflex activity (part b). This chapter define ganglion and indicate the general body location of ganglia, describe the general structure of a nerve, follow the process of nerve regeneration, name the 12 pairs of cranial nerves, indicate the body region and structures innervated by each.
Trang 1PowerPoint ® Lecture Slides
prepared by Janice Meeking, Mount Royal College
The Peripheral Nervous
System and Reflex Activity:
Trang 2Copyright © 2010 Pearson Education, Inc.
• Each nerve is identified by a number
(I through XII) and a name
“On occasion, our trusty truck acts funny—very
good vehicle anyhow”
Trang 3Accessory nerve (XI)
Hypoglossal nerve (XII)
Filaments of olfactory nerve (I)
Olfactory bulb Olfactory tract
Optic chiasma
Optic nerve (II)
Optic tract
Oculomotor nerve (III) Trochlear nerve (IV) Trigeminal nerve (V) Abducens nerve (VI)
Cerebellum Medulla oblongata
Trang 4Copyright © 2010 Pearson Education, Inc. Figure 13.5 (b)
Olfactory Optic Oculomotor Trochlear Trigeminal Abducens
Yes (smell) Yes (vision) No No Yes (general sensation) No
No No Yes Yes Yes Yes
No No Yes No No No
Cranial nerves VII – XII
Sensory function
Motor function
PS*
fibers
Sensory function
Motor function
PS*
fibers
VII VIII
IX X XI XII
Facial Vestibulocochlear
Glossopharyngeal Vagus
Accessory Hypoglossal
Yes (taste) Yes (hearing and balance) Yes (taste) Yes (taste) No No
Yes Some
Yes Yes Yes Yes
Yes No
Yes Yes No No
Trang 5I: The Olfactory Nerves
• Arise from the olfactory receptor cells of nasal cavity
• Pass through the cribriform plate of the
ethmoid bone
• Fibers synapse in the olfactory bulbs
• Pathway terminates in the primary olfactory
cortex
• Purely sensory (olfactory) function
Trang 6Copyright © 2010 Pearson Education, Inc. Table 13.2
Trang 7II: The Optic Nerves
• Arise from the retinas
• Pass through the optic canals, converge and partially cross over at the optic chiasma
• Optic tracts continue to the thalamus, where they synapse
• Optic radiation fibers run to the occipital
(visual) cortex
• Purely sensory (visual) function
Trang 8Copyright © 2010 Pearson Education, Inc. Table 13.2
Trang 9III: The Oculomotor Nerves
• Fibers extend from the ventral midbrain
through the superior orbital fissures to the
extrinsic eye muscles
• Functions in raising the eyelid, directing the eyeball, constricting the iris
(parasympathetic), and controlling lens shape
Trang 10Copyright © 2010 Pearson Education, Inc. Table 13.2
Trang 11IV: The Trochlear Nerves
• Fibers from the dorsal midbrain enter the orbits via the superior orbital fissures to innervate the superior oblique muscle
• Primarily a motor nerve that directs the eyeball
Trang 12Copyright © 2010 Pearson Education, Inc. Table 13.2
Trang 13V: The Trigeminal Nerves
• Largest cranial nerves; fibers extend from pons to face
• Three divisions
• Ophthalmic (V1) passes through the superior orbital fissure
• Maxillary (V2) passes through the foramen rotundum
• Mandibular (V3) passes through the foramen ovale
• Convey sensory impulses from various areas of the face (V1) and (V2), and supplies motor fibers (V3) for mastication
Trang 14Copyright © 2010 Pearson Education, Inc. Table 13.2
Trang 16Copyright © 2010 Pearson Education, Inc.
VI: The Abducens Nerves
• Fibers from the inferior pons enter the orbits via the superior orbital fissures
• Primarily a motor, innervating the lateral
rectus muscle
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VII: The Facial Nerves
• Fibers from the pons travel through the internal
acoustic meatuses, and emerge through the
stylomastoid foramina to the lateral aspect of the
face
• Chief motor nerves of the face with 5 major branches
• Motor functions include facial expression,
parasympathetic impulses to lacrimal and salivary glands
• Sensory function (taste) from the anterior two-thirds
of the tongue
Trang 20Copyright © 2010 Pearson Education, Inc. Table 13.2
Trang 21VIII: The Vestibulocochlear Nerves
• Afferent fibers from the hearing receptors
(cochlear division) and equilibrium receptors (vestibular division) pass from the inner ear through the internal acoustic meatuses, and enter the brain stem at the pons-medulla
border
• Mostly sensory function; small motor
component for adjustment of sensitivity of
receptors
Trang 22Copyright © 2010 Pearson Education, Inc. Table 13.2
Trang 23IX: The Glossopharyngeal Nerves
• Fibers from the medulla leave the skull via the jugular foramen and run to the throat
• Motor functions: innervate part of the tongue and pharynx for swallowing, and provide
parasympathetic fibers to the parotid salivary glands
• Sensory functions: fibers conduct taste and
general sensory impulses from the pharynx
and posterior tongue, and impulses from
carotid chemoreceptors and baroreceptors
Trang 24Copyright © 2010 Pearson Education, Inc. Table 13.2
Trang 25X: The Vagus Nerves
• The only cranial nerves that extend beyond the head and neck region
• Fibers from the medulla exit the skull via the jugular foramen
• Most motor fibers are parasympathetic fibers that
help regulate the activities of the heart, lungs, and abdominal viscera
• Sensory fibers carry impulses from thoracic and
abdominal viscera, baroreceptors, chemoreceptors, and taste buds of posterior tongue and pharynx
Trang 26Copyright © 2010 Pearson Education, Inc. Table 13.2
Trang 27XI: The Accessory Nerves
• Formed from ventral rootlets from the C1–C5region of the spinal cord (not the brain)
• Rootlets pass into the cranium via each
foramen magnum
• Accessory nerves exit the skull via the jugular foramina to innervate the trapezius and
sternocleidomastoid muscles
Trang 28Copyright © 2010 Pearson Education, Inc. Table 13.2
Trang 29XII: The Hypoglossal Nerves
• Fibers from the medulla exit the skull via the hypoglossal canal
• Innervate extrinsic and intrinsic muscles of the tongue that contribute to swallowing and
speech
Trang 30Copyright © 2010 Pearson Education, Inc. Table 13.2