14 The Brain and Cranial Nerves C h a p t e r PowerPoint® Lecture Slides prepared by Jason LaPres Lone Star College - North Harris Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–18 Origins of the Cranial Nerves. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Olfactory Nerves (I) Primary function Origin Pathway Special sensory (smell) Origin Receptors of olfactory epithelium Pathway Olfactory foramina in cribriform plate of ethmoid Destination Olfactory bulbs Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Olfactory Nerve Structures Olfactory bulbs Located on either side of crista galli Olfactory tracts Axons of postsynaptic neurons Leading to cerebrum Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–19 The Olfactory Nerve. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Optic Nerves (II) Primary function Origin Pathway Special sensory (vision) Origin Retina of eye Pathway Optic canals of sphenoid Destination Diencephalon via optic chiasm Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Optic Nerve Structures Optic chiasm Optic tracts Where sensory fibers converge And cross to opposite side of brain Optic tracts Reorganized axons Leading to lateral geniculate nuclei Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–20 The Optic Nerve. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Oculomotor Nerves (III) Primary function Origin Pathway Motor (eye movements) Origin Mesencephalon Pathway Superior orbital fissures of sphenoid Destination Somatic motor: superior, inferior, and medial rectus muscles inferior oblique muscle levator palpebrae superioris muscle Visceral motor: intrinsic eye muscles Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Oculomotor Nerve Structures Oculomotor nerve Controls four of six eye-movement muscles Delivers autonomic fibers to ciliary ganglion: ciliary ganglion: controls intrinsic muscles of iris and lens Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Trochlear Nerves (IV) Primary function Origin Motor (eye movements) Origin Mesencephalon Pathway Superior orbital fissure of sphenoid Destination Superior oblique muscle Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Abducens Nerves (VI) Primary function Origin Motor (eye movements) Origin Pons Pathway Superior orbital fissures of sphenoid Destination Lateral rectus muscle Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–21 Cranial Nerves Controlling the Extra-Ocular Muscles. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Trigeminal Nerves (V) Primary function Origin Mixed (sensory and motor) to face Origin Ophthalmic branch (sensory): orbital structures nasal cavity skin of forehead, upper eyelid, and eyebrow part of nose Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Trigeminal Nerves (V) Origin Maxillary branch (sensory): lower eyelid upper lip, gums, and teeth cheek and nose palate and part of pharynx Mandibular branch (sensory): lower gums, teeth, and lips palate and part of tongue Mandibular branch (motor): motor nuclei of pons Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Trigeminal Nerves (V) Pathway Ophthalmic branch: superior orbital fissure Maxillary branch: foramen rotundum Mandibular branch: foramen ovale Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Trigeminal Nerves (V) Destination Sensory nerves: sensory nuclei in pons Motor nerves of mandibular branch: muscles of mastication Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Trigeminal Nerve Structures Trigeminal nerves Largest cranial nerves With three major branches Semilunar ganglion Contains cell bodies of sensory neurons Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–22 The Trigeminal Nerve. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Facial Nerves (VII) Primary function Origin Pathway Mixed (sensory and motor) to face Origin Sensory: taste receptors on anterior 2/3 of tongue Motor: motor nuclei of pons Pathway Internal acoustic meatus to facial canals (stylomastoid foramina) Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Facial Nerves (VII) Destination Sensory: sensory nuclei of pons Somatic motor: muscles of facial expression Visceral motor: tear and nasal mucous glands submandibular and sublingual salivary glands Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Facial Nerve Structures Facial nerve branches Temporal Zygomatic Buccal Mandibular Cervical branches Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Facial Nerve Structures Geniculate ganglia Hold cell bodies of sensory neurons Pterygopalatine ganglia Postganglionic fibers innervate glands (lacrimal, nasal cavity, and pharynx) Submandibular ganglia Innervate salivary glands Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–23a The Facial Nerve. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–23b The Facial Nerve. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Vestibulocochlear Nerves (VIII) Primary function: special sensory Vestibular branch: balance and equilibrium Cochlear branch: hearing Origin Receptors of inner ear Pathway Internal acoustic meatus of temporal bones Destination Vestibular and cochlear nuclei of pons and medulla oblongata Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Vestibulocochlear Nerve Structures Vestibular branch Originates at receptors of vestibule (balance) Connects to vestibular nuclei of pons and medulla oblongata Cochlear branch Originates at sensors of cochlea (hearing) Connects with cochlear nuclei of pons and medulla oblongata Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–24 The Vestibulocochlear Nerve. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Glossopharyngeal Nerves (IX) Primary function Mixed (sensory and motor) to head and neck Origins Sensory: posterior 1/3 of tongue part of pharynx and palate carotid arteries Motor: motor nuclei of medulla oblongata Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Glossopharyngeal Nerves (IX) Pathway Destination Jugular foramina between occipital and temporal bones Destination Sensory: sensory nuclei of medulla oblongata Somatic motor: nerves involved in swallowing Visceral motor: parotid salivary gland Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Glossopharyngeal Nerve Structures Superior and inferior ganglion Sensory neurons of tongue and pharynx Otic ganglion Synapse visceral motor fibers Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–25 The Glossopharyngeal Nerve. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Vagus Nerves (X) Primary function Origins Mixed (sensory and motor) Widely distributed in thorax and abdomen Origins Sensory: part of pharynx auricle and external acoustic meatus diaphragm visceral organs of thoracic and abdominopelvic cavities Motor: motor nuclei in medulla oblongata Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Vagus Nerves (X) Pathway Destination Jugular foramina Between occipital and temporal bones Destination Sensory: sensory nuclei and autonomic centers of medulla oblongata Visceral motor: muscles of the palate and pharynx muscles of the digestive, respiratory, and cardiovascular systems in thoracic and abdominal cavities Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Vagus Nerve Structures Vagus nerves Branch and radiate extensively Superior (jugular) ganglion and inferior (nodose) ganglion Hold sensory neurons Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–26 The Vagus Nerve. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–26 The Vagus Nerve. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Accessory Nerves (XI) Primary function Origin Motor to muscles of neck and upper back Origin Motor nuclei of spinal cord and medulla oblongata Pathway Jugular foramina between occipital and temporal bones Destination Internal branch: voluntary muscles of palate, pharynx, and larynx External branch: sternocleidomastoid and trapezius muscles Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Accessory Nerve Structures Spinal root Cranial root Motor fibers that originate in anterior gray horns of first five cervical segments of spinal cord Cranial root Motor fibers that originate in medulla oblongata Internal branch Joins the vagus nerve External branch Controls muscles of neck and back Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves The Hypoglossal Nerves (XII) Primary function Origin Motor (tongue movements) Origin Motor nuclei of medulla oblongata Pathway Hypoglossal canals of occipital bone Destination Muscles of tongue Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Figure 14–27 The Accessory and Hypoglossal Nerves. Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Cranial Nerves Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings