cholinergic neurons Flashcards
Cholinergic neurons are those that utilize ___?
Acetylcholine (ACh)
Six sequential steps of neurotransmission
o Synthesis o Storage o Release o Binding of ACh to receptor o Degradation in synaptic cleft o Recycling of choline and acetate
________ will block the degradation and increase time ACh is acting on postsynaptic receptors
ACh esterase inhibitors
What are the Two families distinguished on basis of their different affinities for agents that mimic the action of ACh
Nicotinic
Muscarinic
GPCRs are slower and are seen on nicotinic or muscarinic receptors?
muscarinic
Muscarinic Receptors recognize _____.
muscarine
where are Muscarinic Receptors mainly located
Located primarily (but not exclusively) at the neuroeffector junction of the parasympathetic nervous system
firs three subclasses of muscarininc receptors?
o M1: gastric parietal cells
o M2: cardiac cells and smooth muscle
o M3: bladder, exocrine glands, smooth muscle
Nicotine at [___] stimulates and at [___] inhibits (due to desensitization)
low
high
Locations of nicotine receptors
o CNS
o Adrenal medulla
o Autonomic ganglia
o NMJ
Direct-Acting Cholinergic Agonists Mimic the effects of ____ by binding directly to cholinergic receptors
ACh
Direct-Acting Cholinergic Agonists- As a group these drugs show little _____ so their use is limited
specificity
Indirect-Acting Cholinergic Agonists (AChE inhibitors ) _________which degrades ACh
Inhibits acetylcholinesterase (AChE)
Cholinergic Agonists Effects: what is DUMBBELSS
o Diarrhea o Urination o Miosis o Bronchorrhea** o Bradycardia** o Emesis o Lacrimation o Sweating o Salivation**
Cholinergic Agonists Effects: what is SLUDGEMM
o Salivation o Lacrimation o Urination o Diarrhea o GI upset** o Emesis o Miosis o Muscle spasms**
these Bind to ACh receptors but do NOT trigger the usual receptor-mediated response, they Block Ach from binding to receptor
Cholinergic Antagonists
Cholinergic Antagonists Three main groups/uses
o Muscarinic receptors of the parasympathetic nerves (aka: antimuscarinic agents)
o Nicotinic receptors of the sympathetic and parasympathetic ganglia
o Nicotinic receptor on skeletal muscle (aka: neuromuscular blockers)
these Cause inhibition of all muscarinic functions
Antimuscarinic Agents
Anticholinergic Effects
- Hot as a hare: increased body temperature
- Blind as a bat: mydriasis (dilated pupils), blurred vision
- Dry as a bone: dry mouth, dry eyes, decreased sweat, constipation, urinary retention
- Red as a beet: flushed face
- Mad as a hatter: confusion/delirium/euphoria
- Bloated as a toad: constipation, urinary retention, ileus
- And the heart runs alone: tachycardia
ABCDs of anticholinergic effects:
o Anorexia o Blurry vision o Constipation/ Confusion o Dry Mouth o Sedation/ o Stasis of urine
MANY drugs have anticholinergic effects that are not the main MOA. what are some examples?
Examples: antihistamines, opioid analgesics, antipsychotics, antidepressants, antiemetics, muscle relaxants
