76 terms

Chapter 13-Drugs affecting the autonomic nervous system

Ms. Riles St. Pete College Nsg II-Pharmacology
autonomic nervous system
Exert involuntary control over the contraction of smooth muscle and cardiac muscle, and glandular activity.
central nervous system (CNS)
A major division of the nervous system that consists of the brain and spinal cord.
fight-or-flight response
The response that is initiated under conditions of stress.
parasympathetic nervous system
Activated under nonstressful conditions and produces symptoms called the rest-and-digest response.
peripheral nervous system
A major division of the nervous system that consists of all nervous tissue outside the CNS, including sensory and motor neurons.
rest-and-digest response
A response initiated under non-stressful conditions under the parasympathetic nervous system.
somatic nervous system
Consists of nerves that provide voluntary control over skeletal muscle.
sympathetic nervous system
Activated under conditions of stress, and produces a set of actions called the fight-or-flight response.
Also called the juncture, along the nerve that the action potential travels along.
ganglionic synapse
As the action potential travels along the first nerve, it encounters the first synapse, or juncture. This connection occurs outside the CNS and is therefore called?
preganglionic neuron
The nerve carrying the impulse exiting the spinal cord.
postganglionic neuron
The nerve on the other side of the ganglionic synapse, waiting to receive the impulse.
synaptic transmission
The process of propagating a signal from one cell to another via a synapse.
norepinephrine (NE)
A primary neurotransmitter of the autonomic nervous system.
acetylcholine (Ach)
A primary neurotransmitter of the autonomic nervous system.
Norepinephrine belongs to this class of agents all of which are involved in neurotransmission.
Receptors at the ends of postganglionic sympathetic neurons, which comes from the word adrenalin.
alpha receptors
One of two types of adrenergic receptors.
beta receptors
One of two types of adrenergic receptors.
monoamine oxidase (MAO)
Enzymatically destroys norepinephrine that is not returned to the vessicles for future use.
Nerves releasing acetylcholine (Ach).
nicotinic receptors
Receptors for Ach in the ganglia. Present in skeletal muscle.
muscarinic receptors
Ach receptors with actions closely resembling the poisonous mushroom Amanita muscaria. They are affected by a number of medications.
acetylcholinesterace (AchE)
Rapidly destroys Ach in the synaptic cleft by this enzyme.
Drugs that stimulate the sympathetic nervous system, also called adrenergic agents.
adrenergic antagonists
Inhibits the sympathetic nervous system, also called sympatholytics.
Also called adrenergic antagonists.
Stimulates the parasympathetic nervous system, producing the characteristics of the rest-and-digest response, also called cholinergic agents.
Inhibit the parasympathetic nervous system, also called cholinergic-blocking agents, parasympathlytics, or muscarinic blockers.
myasthenia gravis
A disease characterized by destruction of nicotinic receptors on skeletal muscle.
Key point
The peripheral nervous system is divided into a somatic portion, which is under voluntary control, and an autonomic portion, which is involuntary and controls smooth muscle, cardiac muscle, and glandular secretions.
Key point
Stimulation of the sympathetic division of the autonomic nervous system causes symptoms of the fight-or-flight response, whereas stimulation of the parasympathetic branch induces rest-and-digest responses.
Key point
Drugs can affect nervous transmission across a synapse by preventing the synthesis, storage, or release of the neurotransmitter; by preventing the destruction of the neurotransmitter; or by binding neurotransmitters to the receptors.
Key point
Norepinephrine is the primary neurotransmitter released at adrenergic receptors, which are divided into alpha and beta subtypes. Acetylcholine is the other primary neurotransmitter of the autonomic nervous system.
Key point
Acetylcholine is the primary neurotransmitter released at cholinergic receptors (nicotinic and muscarinic) in both the sympathetic and parasympathetic nervous systems. It is also the neurotransmitter at nicotinic receptors in skeletal muscle.
Key point
Autonomic drugs are classified by the receptors they stimulate or block: Sympathomimetics stimulate sympathetic nerves, and parasympathomimetics stimulate parasympathetic nerves; adrenergic antagonists inhibit the sympathetic division, whereas anticholinergics inhibit the parasympathetic branch.
Key point
Sympathomimetics act by directly activating adrenergic receptors, or indirectly by increasing the release of norepinephrine from nerve terminals. They are used primarily for their effects on the heart, bronchial tree, and nasal passages.
Key point
Adrenergic antagonists are used primarily for hypertension and are the most widely prescribed class of autonomic drugs.
Key point
Parasympathomimetics act directly by stimulating cholinergic receptors or indirectly by inhibiting acetylcholinesterase. They have few therapeutic uses because of their numerous side effects.
Key point
Anticholinergics act by blocking the effects of acetylcholine at muscarinic receptors, and are used to dry secretions, treat asthma, and prevent motion sickness.
The two primary divisions of the nervous system.
This nervous system provides involuntary control over smooth muscle, cardiac muscle, and glands.
Fight or flight response
Produced by the sympathetic nervous system.
Rest and digest response
Produced by the parasympathetic nervous system.
presynaptic, synapse cleft, and postsynaptic
Three parts of a synapse.
Sympathetic nerves are often called this, a term coming from the word adrenaline.
Parasympathetic nerves are called this.
parasympathetic and sympathetic
Increased heart rate, bronchodilation, decreased motility in the GI tract, mydriasis, and decreased secretions from glands are physiologic responses associated with inactivation of this nervous system or activation of the what nervous system.
These blockers are primarily used for hypertension, and comprise the most commonly prescribed autonomic medications.
sympathomimetic or adrenergic drugs
This class of drugs is named after the fight-or-flight response and primarily used for increasing the heart rate, dilating the bronchi, and drying secretions resulting from colds.
These drugs are named after the rest-and-digest response, and are commonly used to stimulate the urinary or digestive tracts following general anesthesia.
Cholinergic (muscarinic) blockers
Cause dry mouth, constipation, urinary retention, and increased heart rate.
Relax vascular smooth muscle and dry nasal secretions.
Cause bronchodilation.
Lower blood pressure without affecting the heart.
Decrease heart rate.
Scopolamine (Hyoscine)
Phenylephrine (Neo-Synephrine)
Bethanechol (Urecholine)
Adrenergic blocker
Propranolol (Inderal)
Dobutamine (Dobutrex)
Return for lab tests to monitor renal function
A patient is discharged with a newly prescribed antagonist for control of hypertension. The nurse gives discharge instructions. It is inappropriate to include which of the following instructions prior to the patient's leaving?
Inhibition of the sympathetic nervous system
An adrenergic blocker is most directly related to which of the following?
Stimulates cholinergic receptors
How does bethanechol (Urecholine) exert its effects?
What drugs block the action of norepinephrine at alpha- and beta-receptors?
Monitor patency throughout the infusion
A nurse is to give phenylephrine parenterally. What safety precaution would be necessary especially with this drug?
myasthenia gravis
Parasympathomimetics are safe for patients diagnosed with which of the following?
Blocks the beta-receptors
How does propanolol (Inderal) exert its effects?
Hypertension, insomnia, and tachycardia
Pseudoephedrine has been ordered for a patient with nasal congestion. The nurse knows the drug can give which of the following side effects?
Decreases gastric acid secretions
Anticholinergics may be used in treatment of peptic ulcers. What action makes this drug useful in this condition?
Adrenergic agonists
What are sympathomimetics also called?
It causes more autonomic side effects.
Epinephrine is a nonselective adrenergic agonist. What is the disadvantage of this nonspecific action?
Take drug on a full stomach
A patient is prescribed Mestinon for myasthenia gravis. Which of the following would be inappropriate to teach the patient?
Cholinergic blocker
Neostigmine is an example of which of the following?
Atropine (Isopto Atropine)
Which of the following drugs would dry up body secretions?
Increase in intraocular pressure
Atropine is usually not prescribed for any patient with glaucoma. The nurse knows the contraindications is due to which of the following effects of atropine?