Lecture Human anatomy and physiology - Chapter 14: The autonomic nervous system

Chapter 14 provides knowledge of the autonomic nervous system. In this chapter, you will learn to: Define autonomic nervous system and explain its relationship to the peripheral nervous system; compare the somatic and autonomic nervous systems relative to effectors, efferent pathways, and neurotransmitters released; compare and contrast the functions of the parasympathetic and sympathetic divisions;...
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Lecture Human anatomy and physiology - Chapter 14: The autonomic nervous system PowerPoint® Lecture Slides prepared by Janice Meeking, Mount Royal College CHAPTER 14 The Autonomic Nervous SystemCopyright © 2010 Pearson Education, Inc. Autonomic Nervous System (ANS) • The ANS consists of motor neurons that: • Innervate smooth and cardiac muscle and glands • Make adjustments to ensure optimal support for body activities • Operate via subconscious controlCopyright © 2010 Pearson Education, Inc. Autonomic Nervous System (ANS) • Other names • Involuntary nervous system • General visceral motor systemCopyright © 2010 Pearson Education, Inc. Central nervous system (CNS) Peripheral nervous system (PNS) Sensory (afferent) Motor (efferent) division division Somatic nervous Autonomic nervous system system (ANS) Sympathetic Parasympathetic division divisionCopyright © 2010 Pearson Education, Inc. Figure 14.1 Somatic and Autonomic Nervous Systems • The two systems differ in • Effectors • Efferent pathways (and their neurotransmitters) • Target organ responses to neurotransmittersCopyright © 2010 Pearson Education, Inc. Effectors • Somatic nervous system • Skeletal muscles • ANS • Cardiac muscle • Smooth muscle • GlandsCopyright © 2010 Pearson Education, Inc. Efferent Pathways • Somatic nervous system • A, thick, heavily myelinated somatic motor fiber makes up each pathway from the CNS to the muscle • ANS pathway is a two-neuron chain 1. Preganglionic neuron (in CNS) has a thin, lightly myelinated preganglionic axon 2. Ganglionic neuron in autonomic ganglion has an unmyelinated postganglionic axon that extends to the effector organCopyright © 2010 Pearson Education, Inc. Neurotransmitter Effects • Somatic nervous system • All somatic motor neurons release acetylcholine (ACh) • Effects are always stimulatory • ANS • Preganglionic fibers release ACh • Postganglionic fibers release norepinephrine or ACh at effectors • Effect is either stimulatory or inhibitory, depending on type of receptorsCopyright © 2010 Pearson Education, Inc. Neuro- Cell bodies in central transmitter Effector nervous system Peripheral nervous system at effector organs Effect Single neuron from CNS to effector organs NERVOUS SOMATIC SYSTEM ACh + Heavily myelinated axon Stimulatory Skeletal muscle Two-neuron chain ...