Lecture Human anatomy and physiology - Chapter 13: The peripheral nervous system and reflex activity (part b)

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.

PowerPoint® Lecture Slides prepared by Janice Meeking, Mount Royal College CHAPTER 13 The Peripheral Nervous System and Reflex Activity: Part B Copyright © 2010 Pearson Education, Inc Cranial Nerves • Twelve pairs of nerves associated with the brain • Most are mixed in function; two pairs are purely sensory • Each nerve is identified by a number (I through XII) and a name “On occasion, our trusty truck acts funny—very good vehicle anyhow” Copyright © 2010 Pearson Education, Inc Frontal lobe Temporal lobe Infundibulum Facial nerve (VII) Vestibulocochlear nerve (VIII) Glossopharyngeal nerve (IX) Vagus nerve (X) Accessory nerve (XI) Hypoglossal nerve (XII) Filaments of olfactory nerve (I) Olfactory bulb Olfactory tract Optic nerve (II) Optic chiasma Optic tract Oculomotor nerve (III) Trochlear nerve (IV) Trigeminal nerve (V) Abducens nerve (VI) Cerebellum Medulla oblongata (a) Copyright © 2010 Pearson Education, Inc Figure 13.5 (a) I II III IV V Cranial nerves I – VI Sensory function Motor function PS* fibers Olfactory Optic Oculomotor Trochlear Trigeminal Yes (smell) Yes (vision) No No Yes (general sensation) No No Yes Yes Yes No No Yes No No No Yes No Sensory function Motor function PS* fibers Yes (taste) Yes (hearing and balance) Yes Some Yes No Yes (taste) Yes (taste) No No Yes Yes Yes Yes Yes Yes No No VI Abducens Cranial nerves VII – XII VII Facial VIII Vestibulocochlear IX X XI XII (b) Copyright © 2010 Pearson Education, Inc Glossopharyngeal Vagus Accessory Hypoglossal *PS = parasympathetic Figure 13.5 (b) I: 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 Copyright © 2010 Pearson Education, Inc Copyright © 2010 Pearson Education, Inc Table 13.2 II: 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 ã Purely sensory (visual) function Copyright â 2010 Pearson Education, Inc Copyright © 2010 Pearson Education, Inc Table 13.2 III: 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 Copyright © 2010 Pearson Education, Inc Copyright © 2010 Pearson Education, Inc Table 13.2 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 Copyright © 2010 Pearson Education, Inc Copyright © 2010 Pearson Education, Inc Table 13.2 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 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 Copyright © 2010 Pearson Education, Inc Copyright © 2010 Pearson Education, Inc Table 13.2 Copyright © 2010 Pearson Education, Inc Table 13.2 VIII: 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 Copyright © 2010 Pearson Education, Inc Copyright © 2010 Pearson Education, Inc Table 13.2 IX: 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 Copyright © 2010 Pearson Education, Inc Copyright © 2010 Pearson Education, Inc Table 13.2 X: 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 Copyright © 2010 Pearson Education, Inc Copyright © 2010 Pearson Education, Inc Table 13.2 XI: The Accessory Nerves • Formed from ventral rootlets from the C1–C5 region 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 Copyright © 2010 Pearson Education, Inc Copyright © 2010 Pearson Education, Inc Table 13.2 XII: 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 Copyright © 2010 Pearson Education, Inc Copyright © 2010 Pearson Education, Inc Table 13.2 ... 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. .. Table 13.2 IX: 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