Chapter 34 The Autonomic Nervous System
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Autonomic Nervous System Includes two neurotransmitters Norepinephrine and acetylcholine Two branches 1. Sympathetic Adrenergic nervous system 2. Parasympathetic Cholinergic (continues)
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Nerve Impulse Transmission (continued) 1. Neurotransmitter (NT) is synthesized from substances that enter or may enter neuron in intact form. 2. Neurotransmitter is stored in storage vesicles. 3. When neuron is stimulated, some storage vesicles fuse with neuron cell membranes and 4. discharge neurotransmitter into the synaptic space. 5. Some neurotransmitter diffuses to the receptor in the effector cell and produces a cell response. 6. Neurotransmitter remaining in the synaptic space is either degraded by enzymes (e.g., monoamine oxidase) or 7. it reenters the neuron and is again stored by storage vesicles.Numbered list
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Sympathetic Nervous System (SNS) Stimulates vital organs Suppresses nonvital body functions Signs of stimulation of the SNS Pupil dilation Bronchiole dilation Increased rate and force of contraction Blood vessel dilation in muscle tissue Increased breakdown of glycogen to glucose
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved The Autonomic Nervous System Agents Sympathetic nervous system receptors Alpha Found in smooth muscle tissue of peripheral blood vessels and in the sphincters of the gastrointestinal and genitourinary system Beta Found mainly in the heart, lungs, and brain
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Parasympathetic Nervous System (PNS) One neurotransmitter Acetylcholine Conserves energy Promotes nutrient use
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Drugs Affecting the ANS Sympathomimetic: adrenergic drugs Stimulate the system Sympatholytic: adrenergic blocking drugs Block alpha and beta receptors (continues)
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Drugs Affecting the ANS Parasympathomimetic: cholinergic drugs Mimic the PNS Parasympatholytic: anticholinergic drugs Block acetylcholine receptors (continued)
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Adrenergic Blockers Treat Hypertension Migraine headache Side effects/adverse effects Hypotension Dizziness
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Adrenergic Blockers: Geriatric Considerations Increase sensitivity to adrenergic drugs Monitor for: Chest pain Palpitations Blurred vision Headache Seizures Hallucinations
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Cholinergics Stimulate the PNS Treat Conditions with poor muscular contraction Neurogenic bladder Glaucoma Cardiac arrhythmias
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Cholinergics: Geriatric Considerations Increase sensitivity to cholinergic drugs Monitor for: Diarrhea Increased bronchoconstriction Increased bronchial secretions Increased lacrimation Blurred vision
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Anticholinergics Action Decrease gastrointestinal and respiratory secretions Dilate bronchioles Dilate pupils Treat Nausea Urinary incontinence Overactive bladder
Copyright 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved Anticholinergics: Geriatric Considerations Increase sensitivity to anticholinergic drugs Hyperthermia Urinary retention Decreased appetite