Chapter 11.B The Nervous System Essentials of Human Anatomy & Physiology Seventh Edition Elaine N. Marieb William A. Simmons Chapter 11.B The Nervous System

Organization of the Nervous System Central Nervous System Peripheral Nervous System Brain Spinal cord Efferent Afferent Efferent Autonomic Motor Sympathetic Parasympathetic

Cranial Nerves - know 12 pairs of nerves that mostly serve the head and neck (1 major exception) Numbered in order, front to back using Roman Numerals (I, II, III, IV, V, VI, etc.) Most are mixed nerves (sensory and motor)

Distribution of Cranial Nerves Figure 7.21 Slide 7.59 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Cranial Nerves – Fill in table! I Olfactory nerve – sensory for smell II Optic nerve – sensory for vision III Oculomotor nerve – motor fibers to eye muscles IV Trochlear – motor fiber to eye muscles Slide 7.60 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Cranial Nerves V Trigeminal nerve – sensory for the face; motor fibers to chewing muscles VI Abducens nerve – motor fibers to eye muscles VII Facial nerve – sensory for taste; motor fibers to the face VIII Vestibulocochlear nerve – sensory for balance and hearing Slide 7.61 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Cranial Nerves IX Glossopharyngeal nerve – sensory for taste; motor fibers to the pharynx X Vagus nerves – sensory and motor fibers for pharynx, larynx, and viscera XI Accessory nerve – motor fibers to neck and upper back XII Hypoglossal nerve – motor fibers to tongue Slide 7.62 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Cranial Nerve Exams http://www.youtube.com/watch?v=a0vtkXMr7qQ

Autonomic Nervous System The involuntary branch of the nervous system Consists of only motor nerves Divided into two divisions Sympathetic division (“fight, fright, flight” – or “stress and aggression”) Parasympathetic division (“rest and digest” – or “feed and breed”) Slide 7.67 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Differences Between Somatic and Autonomic Nervous Systems Nerves Somatic – one motor neuron Autonomic – preganglionic and postganglionic nerves Effector organs Somatic – skeletal muscle Autonomic – smooth muscle, cardiac muscle and glands Slide 7.68a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Differences Between Somatic and Autonomic Nervous Systems Nerurotransmitters Somatic – always use acetylcholine Autominic – use acetylcholine, epinephrine, or norepinephrine Slide 7.68b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Comparison of Somatic and Autonomic Nervous Systems Figure 7.24 Slide 7.69 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Anatomy of the Sympathetic Division Originates from T1 through L2 Ganglia are at the sympathetic trunk (near the spinal cord) Short pre-ganglionic neuron and long postganglionic neuron transmit impulse from CNS to the effector Norepinephrine and epinephrine are neurotransmitters to the effector organs Slide 7.70 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Sympathetic Pathways Figure 7.26 Slide 7.71 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Anatomy of the Parasympathetic Division Originates from the brain stem and S1 through S4 Terminal ganglia are at the effector organs Always uses acetylcholine as a neurotransmitter Slide 7.72 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Anatomy of the Autonomic Nervous System Figure 7.25 Slide 7.73 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Autonomic Functioning Sympathetic – “fight-or-flight” (or fright) Response to unusual stimulus Takes over to increase activities Remember as the “E” division = exercise, excitement, emergency, and embarrassment Slide 7.74a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Autonomic Functioning Parasympathetic – housekeeping activites Conserves energy Maintains daily necessary body functions Remember as the “D” division - digestion, defecation, and diuresis (urination) Slide 7.74b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings