ELAINE N. MARIEB EIGHTH EDITION 7 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY PART B The Nervous System

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I. Peripheral Nervous System 1) The PNS consists 2) Structure of a nerve: a) Nerve: b) Endoneurium: c) Perineurium: d) Epineurium:

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings e) Classified as: 1. Sensory: 2. Motor: 3. Mixed: 3) Cranial nerves: 12 pairs of nerves, that branch off the brain and serve mainly the head & neck 4) Numbered in order using Roman numerals

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cranial Nerves 5) NumberName Function  I Olfactory nerve –Smell  II Optic nerve – Sight  III Oculomotor–eye movement  IV Trochlear – eye movement  V Trigeminal nerve –face sensation & chewing  VI Abducens nerve – Lateral Eye movement  VII Facial nerve – Move face & taste

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cranial Nerves  VIII Acoustic (Vestibulocochlear) – hearing and balance  IX Glossopharyngeal nerve – swallow and taste  X Vagus nerves – Regulates heart  XI Accessory nerve – Neck and shoulder movement  XII Hypoglossal nerve – Moves tongue

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6) Spinal Nerves: a) 31 pairs of nerves that branch off of the spinal cord b) C 1-8, T 1-12, L 1-5, S 1-5, coccygeal c) Plexus: complex network of nerves that serve the motor and sensory needs of the limbs

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Spinal Nerves Figure 7.22a

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings II. Autonomic Nervous System 1) The ANS 2) The relative stability of our internal environment depends on this system 3) The ANS consists of a 2 neuron chain: a) Preganglionic axon: From the CNS to the ganglion b) Postganglionic axon: From the ganglion to the effector

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 4) The divisions: a) Sympathetic: 1. Functions during extreme situations (fight or flight reflex) 2. Rapid HR, breathing, cold, sweaty skin, dilated pupils 3. Work when emotionally or physically stressed 4. Continues for several minutes after until hormones are broken down

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings b) Parasympathetic: 1. Functions to conserve the body 2. Opposite of sympathetic, promotes digestion and waste elimination

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 7.24 Comparison of Somatic and Autonomic Nervous Systems

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 1) Pain originating within visceral organs is not well localized 2) Referred pain: Feeling pain from an organ on the body surface(Kidney pain= back ache) 3) Phantom pain: Pain felt in a lost limb due to stimulation of the nerve that use to go there III. Referred pain

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 4) Psychogenic pain: pain without a medical cause 5) Headache: A) The brain has no pain receptors, so headaches are unusual B) Probably due to 1. Blood vessel constriction 2. Sinus pressure 3. Over stimulation 4) Muscle spasms C) Migraine: Severe long lasting headache (triggered by food, emotions, light)

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings 1) Learning and memory are located in the cerebrum 2) Believed to be due to RNA changes and neuron connections 3) Sleep: A) We spend about 1/3 of our life asleep (25 Yrs) B) Sleep is essential to good mental and physical health IV: Learning memory and sleep

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings C) Caused by build up of chemicals in the thalamus D) Insomnia: Light or difficult sleep 4) Dreaming: A) About 1/5 of time asleep (5YRS) B) Last from a few minutes to 45 minutes C) Seem longer, due to cutting out unimportant activity D) More frequent near waking

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings E) REM (Rapid eye movement) indicates dreaming F) Believed to be important to normal health