Cholinergics: General Flashcards
Muscarinic receptor agonists are:
parasympathomimetics
direct agonists of muscarinic receptors
produce
effects similar to those observed during the stimulation of post-ganglionic
parasympathetic nerves
Acetylcholinesterase inhibitors (anticholinesterase agents)
- agents that enhance the effects of endogenously released acetylcholine by blocking its natural breakdown by the enzyme acetylcholinesterase
What site is achetycholinesterase inhibitors used at?
- effective at any site where acetylcholine is the neurotransmitter
Muscarinic receptor antagonists are:
(parasympatholytics, antimuscarinic agents)
Muscarinic receptor antagonist work by competitively block muscarinic receptors - interfere with responses that result from________ stimulation
parasympathetic
competitive antagonists for nicotinic receptors (NN) at autonomic ganglia
Ganglionic blocking agents (neural nicotinic receptor antagonists)
Ganglionic blocking agents interfere with ganglionic transmission of
both parasympathetic and sympathetic
nerves
block neurotransmission at the neuromuscular junction producing paralysis of skeletal muscle
Neuromuscular junction blocking agents
Response of eye to muscarinic receptor
Contraction of the ciliary muscle to focus lens for near vision
Contraction of the iris sphincter muscle causing miosis
Response of heart to muscarinic receptor
decreased rate
Response of lung to muscarinic receptor
Constriction of bronchi
Promotion of secretions
Response of bladder to muscarinic receptor
voiding
Response of GI tract to muscarinic receptor
Salivation Increased gastric secretions Increased intestinal tone and motility
Response of bladder tract to muscarinic receptor
Generalized sweating
Nicotinic NM (muscle): Skeletal muscle action is
end-plate depolarization and contraction
Nicotinic NN (neural) Autonomic ganglia
depolarization and firing of post-ganglionic neurons
Nicotinic NN (neural) Adrenal medulla
depolarization and secretion of catecholamines
Nicotinic (CNS)
Brain and spinal cord
control of neurotransmitter release
MUSCARINIC RECEPTOR AGONISTS - direct agonists of muscarinic receptors; produce effects similar to those observed during
the stimulation of :
post-ganglionic parasympathetic nerves (parasympathomimetics)
Muscarinics receptors are:
G-protein receptors so are slower then nicotinic
Nicotinic receptors are
ion-gated so are faster then muscarinic
Muscarinic and nicotinic both use_____ as their NT
Ach
______ is responsible for EPSP after binding of Ach
nicotinic
Which uses second messenger system: nicotinic or muscarinic
muscarinic
The parasympathetic nervous system, which uses acetylcholine almost exclusively to send its messages, is said to be almost entirely
cholinergic
