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. | 13 The Peripheral Nervous System and Reflex Activity: Part B 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” Figure (a) Frontal lobe Temporal lobe Infundibulum Facial nerve (VII) Vestibulo- cochlear nerve (VIII) Glossopharyngeal nerve (IX) Vagus nerve (X) Accessory nerve (XI) Hypoglossal nerve (XII) (a) 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 Figure (b) *PS = parasympathetic (b) Cranial nerves I – VI I II III IV V VI 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 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 Table 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 Purely sensory (visual) function Table III: The Oculomotor Nerves Fibers extend from the ventral midbrain through the superior orbital fissures to the extrinsic eye muscles Functions in . | 13 The Peripheral Nervous System and Reflex Activity: Part B 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” Figure (a) Frontal lobe Temporal lobe Infundibulum Facial nerve (VII) Vestibulo- cochlear nerve (VIII) Glossopharyngeal nerve (IX) Vagus nerve (X) Accessory nerve (XI) Hypoglossal nerve (XII) (a) 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 Figure (b) *PS = parasympathetic (b) Cranial nerves I – VI I II III IV V VI 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 .
