PRELIMS: Drugs Affecting ANS Flashcards
Controls functions not consciously controlled.in the ANS
Visceral and Involuntary
Contains clusters of nerve cell bodies. in the ANS
Peripheral Ganglia & Plexuses
Unmyelinated, which affects transmission speed. in the ANS
Postganglionic Fibers
What is the main effect of cevimeline in treating Sjogren’s syndrome?
It is an M1 and M3 agonist used to treat xerostomia.
What is the predominant tone in the heart under normal conditions?
Cholinergic (parasympathetic).
What is the main difference between parasympathomimetic and parasympatholytic drugs?
Parasympathomimetic drugs mimic the effects of the parasympathetic nervous system, while parasympatholytics oppose these effects.
Which drug is used to treat xerostomia due to decreased salivary secretion?
Pilocarpine
Which drug is used for diagnosing bronchial hyper-reactivity?
Methacholine.
What is the receptor type and location for nicotinic receptors?
What is the receptor type and location for nicotinic receptors?
What is the primary action of choline esters like methacholine, carbachol, and bethanechol?C
They act as cholinoceptor agonists with varying effects: methacholine (M>N effect), carbachol (greater N effect), and bethanechol (mainly M effect).
Which muscarinic receptor subtype is associated with the inhibition of cAMP production?
M2 and M4 receptors.
What are the chemical mediators for the sympathetic nervous system?
Norepinephrine.
What is the receptor type and location for muscarinic receptors?
Muscarinic receptors are G-protein coupled receptors located in smooth muscles and cardiac muscles.
What are alkaloids in the context of parasympathomimetics?
Alkaloids include muscarine, pilocarpine, nicotine, lobeline, and arecoline. They are tertiary amines, well absorbed from most administration sites, and muscarine is less completely absorbed from the GI tract.
Where are the ganglia of the parasympathetic nervous system typically located?
Near or at the organ.
What type of response is associated with the sympathetic nervous system?
Fight, flight, fright; massive discharge.
What is the typical length of preganglionic and postganglionic fibers in the sympathetic nervous system?
Preganglionic fibers are short, and postganglionic fibers are long.
What are parasympathomimetic drugs?
Drugs that mimic the effects of the parasympathetic nervous system.
What neurotransmitter is primarily associated with the parasympathetic nervous system?
Acetylcholine
What is the main characteristic of the autonomic nervous system (ANS)?
The ANS is visceral and involuntary, controlling functions not consciously regulated.
What is the difference between direct and indirect parasympathomimetic?
Direct parasympathomimetics are agonists that directly activate parasympathetic receptors. Indirect parasympathomimetics include acetylcholine esterase inhibitors that prevent the breakdown of acetylcholine, increasing its action.
What are parasympatholytic drugs?
Drugs that oppose the effects of the parasympathetic nervous system.
What is the primary use of methacholine?
Methacholine is used to diagnose bronchial hyper-reactivity and has an M>N effect.
What are choline esters and their general characteristics?
Choline esters include methacholine, carbachol, and bethanechol. They are relatively insoluble in lipids, contain a quaternary ammonium group, are poorly absorbed and hydrolyzed in the GI tract, and have poor CNS distribution.