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