McKenna's Pharmacology for Nursing, 2e

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Introduction to the autonomic nervous system

Learning objectives Upon completion of this chapter, you should be able to: 1. Describe how the autonomic nervous system differs anatomically from the rest of the nervous system. 2. Outline a sympathetic response and the clinical manifestation of this response. 3. Describe the alpha(α)- and beta(β)-receptors found within the sympathetic nervous system by sites and actions that follow the stimulation of each kind of receptor. 4. Outline the events that occur with stimulation of the parasympathetic nervous system. 5. Define the terms muscarinic receptor and nicotinic receptor, giving an example of each.

Test your current knowledge of the autonomic nervous system with a PrepU Practice Quiz!

Glossary of key terms acetylcholinesterase: enzyme responsible for the immediate breakdown of acetylcholine when released from the nerve ending; prevents overstimulation of cholinergic receptor sites adrenergic receptors: receptor sites on effectors that respond to noradrenaline alpha-receptors (α-receptors): adrenergic receptors that are found in smooth muscles autonomic nervous system: portion of the central and peripheral nervous systems that, with the endocrine system, functions to maintain internal homeostasis beta-receptors (β-receptors): adrenergic receptors that are found in the heart, lungs and vascular smooth muscle

cholinergic receptors: receptor sites on effectors that respond to acetylcholine ganglia (pl.; sing. ganglion): groups of closely packed nerve cell bodies monoamine oxidase (MAO): enzyme that breaks down noradrenaline to make it inactive muscarinic receptors: cholinergic receptors that also respond to stimulation by muscarine nicotinic receptors: cholinergic receptors that also respond to stimulation by nicotine

parasympathetic nervous system: “rest-and-digest” response mediator that contains central nervous system (CNS) cells from the cranium or sacral area of the spinal cord, long preganglionic axons, ganglia near or within the effector tissue and short postganglionic axons that react with cholinergic receptors sympathetic nervous system: “fight-or-flight” response mediator; composed of CNS cells from the thoracic or lumbar areas, short preganglionic axons, ganglia near the spinal cord and long postganglionic axons that react with adrenergic receptors