Ch. 13 Anatomy of the Nervous System … PERIPHERAL N.S. © 2013 Pearson Education, Inc.

The Peripheral Nervous System Components: Central nervous system (CNS) Peripheral nervous system (PNS) (1) Sensory receptors (2) Motor endings (3) Nerves and Ganglia Sensory (afferent) division Motor (efferent) division Somatic nervous system Autonomic nervous system (ANS) Sympathetic division Parasympathetic division

I. Sensory Receptors & Sensation A. Sensory Receptors 1. Definition/Function

Sensory Receptors … 4. Classification: Chart Lab 7 a) *Location -Extero-, Intero, Proprio-ceptors b) *Structure- encapsulated or not c) Stimuli Received Mechanoreceptors: Proprioceptors (location) *Photoreceptors: *Chemoreceptors: *Thermoreceptors: *Nocireceptors: Mechanoreceptors

B. Nerves 1. Structure and Classification *a. Nerve = b. *Connective Tissue of Nerves *Endoneurium *Perineurium *Epineurium c. *Fascicle d. *Vasa Nervorum e. *Neurilemma *Schwann neuron f. *Node of Ranvier Remember skeletal muscle: (endomysium, perimysium, epimysium) Figure 7.23

Structure and Classification … c. Classification of Nerves Information Carried *Mixed Nerves = Types of fibers: *Pure Sensory- Pure Motor ii. Location

Hypoglossal nerve (XII) 1. Cranial Nerves 12 paired Know: name, number, functions, and brain regions involved Filaments of olfactory nerve (I) Frontal lobe Olfactory bulb Olfactory tract Optic nerve (II) Temporal lobe Optic chiasma Optic tract Oculomotor nerve (III) Infundibulum Facial nerve (VII) Trochlear nerve (IV) Vestibulocochlear nerve (VIII) Trigeminal nerve (V) Glossopharyngeal nerve (IX) Abducens nerve (VI) Vagus nerve (X) Cerebellum Accessory nerve (XI) Medulla oblongata Hypoglossal nerve (XII) © 2013 Pearson Education, Inc.

OVERVIEW Type of Nerves: - 3 all Sensory: I, II, VIII - 9 (the rest) ARE ALL MIXED RULE: if motor to muscle, then always has proprioception - 5 of 9 mostly Motor (really mixed): III Occulomotor IV Trochlear, VI Abducens XI Spinal Accessory XII Hypoglossal - 4 of 9 Mostly Mixed: V, VII, IX, X - 4 Have Autonomic: III, V, IX, and X = mostly autonomic - Ipsilateral: no crossing over © 2013 Pearson Education, Inc.

"On occasion, our trusty truck acts funny—very good vehicle anyhow" Overview … Memory Device "On occasion, our trusty truck acts funny—very good vehicle anyhow" "Oh once one takes the anatomy final, very good vacations are heavenly" Figure 13.6b Location and function of cranial nerves (Marieb) Cranial nerves I – VI Sensory function Motor function PS* fibers Cranial nerves VII – XII Sensory function Motor function PS* fibers I II III IV V VI Olfactory Optic Oculomotor Trochlear Trigeminal Abducens Yes (smell) Yes (vision) No Yes (general sensation) No Yes No Yes VII VIII IX X XI XII Facial Vestibulocochlear Glossopharyngeal Vagus Accessory Hypoglossal Yes (taste) Yes (hearing and balance) No Yes Some Yes No Cranial nerves I – VI Sensory function Motor function PS* fibers Cranial nerves VII – XII Sensory function Motor function PS* fibers *PS = parasympathetic Sympathetic axons are all in Spinal Nerves © 2013 Pearson Education, Inc.

1. Cranial Nerves … a) The Olfactory Nerves = I Sensory: from: olfactory bulbs  Olfactory tract  Cortex = © 2013 Pearson Education, Inc.

b) Optic Nerves = II *Sensory from: *optic chiasma: *Cerebral Cortex Region: © 2013 Pearson Education, Inc.

c) The Oculomotor Nerves = III *Location: midbrain Motor-mostly *4 eye muscles: _______________________ (except Sup Obl & Lat Rect) From Cortex: Parasympathetic Motor Lens: Cilliary Muscles Sensory: Proprioception - To Cortex: © 2013 Pearson Education, Inc.

d) IV = The Trochlear Nerves Mixed, mostly motor Location: Midbrain *Motor: Sensory: Proprioception © 2013 Pearson Education, Inc.

e) V = The Trigeminal Nerves Location: Lateral pons Mixed Face *Sensory: Proprioceptors To Cortex: -- *Motor: From Cortex: 3 Branches: mostly sensory—Ophthalmic, Maxillary, & Mandibular has somatic m © 2013 Pearson Education, Inc.

f) VI = The Abducens Nerves Location: posterior Pons Mixed– mostly motor *Motor  Sensory: proprioception © 2013 Pearson Education, Inc.

g) VII = The Facial Nerves Location: Pons Mixed *Motor *Somatic Motor for: - To Cortex:  Parasympathetic: salivary glands (submandibular & sublingual) and lacrimal glands Sensory function Proprioeptors anterior 2/3 taste buds © 2013 Pearson Education, Inc.

h) VIII = The Vestibulocochlear Nerves Location: Pons-Medulla border Sensory (mostly) *Sensory: 1) 2) - To Cortex: © 2013 Pearson Education, Inc.

i) IX = The Glossopharyngeal Nerves Location: medulla Mixed Motor Muscles of Sensory Proprioception © 2013 Pearson Education, Inc.

j) X = The Vagus Nerves Location: Lateral medulla Nerve extends beyond head Mixed Motor– mostly Autonomic *Parasympathetic Organs: skeletal muscles of larynx and pharynx Sensory– visceral: © 2013 Pearson Education, Inc.

k) XI = The Accessory Nerves (Spinal Accessory) *Location: Mixed– mostly motor Motor: Head & Neck muscles trapezius & sternocleidomastoid muscles Sensory proprioception © 2013 Pearson Education, Inc.

l) XII = The Hypoglossal Nerves Location: Medulla: near midline, inferior to abducens Mixed– mostly motor Motor: Tongue muscles & muscles attached to Tongue for manipulation of food Sensory: proprioception © 2013 Pearson Education, Inc.