Alpha and Beta Antagonist ppt Flashcards
The autonomic nerouns are divided into what 2 parts
preganglionic and post ganglionic
which sneurons leaves the spinal cord fromthe cranial, thoracic and lumbar or sacral region to form a synaptic connection
preganglionic
which nerons section sends their axons directly to the effector organ?
post ganglionic
Most Postganglionic autonomic nerves are what?
Nonmylinated and have slow conductino
Most preganglionic neurons are what
mylinated an dhave fast conduction
there are ___ segmentally arranged ganglia that cansit of 2 chains bilat down spinal cord
22
which ganlionic nerves are short and which are long?
pre short
post long
what NT mediates synaptic transmission B/T preganglionic and post ganglionic nerve fiber in the Sympathetic pathway
ACh
what is the NT if the postganglionic sypathetic nerve pathway (at the end organ junction)
NE
sites that use ACh as their NT are termed
cholinergic
sites that use NE as the NT are termed
adrenergic
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the adrenal Medulla unlike the postganglionic sympathetic nerve terminal, releases what as it’s primary catecholamine
Epinephrine
a good pic to refer to notice the short preganlionic neurons and the long postganglionic neurons.
also notice the PNS vs the SNS and thier NT
Autonomic regulation of periphreral involuntary organs
most organs receive duel innervation consiting of _____ and _____ components
if blockade of one system is acheived it leads to ________ of response by the other
SNS and PNS
exaggeration
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in both the SNS and PNS ganglia the NT released by the preganglionic neurons is what?
ACh
another pic to look at understand and master
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the postganglionic sympathetic NT is what
NE
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the post ganglionic parasympathetic NT is what
ACh
how is ACh broken down
via acetylcholinesterase into acetic acid and choline
How is NE broken down
MAO
COMT
what are the 2 types of ADRENERGIC receptors
alpha
Beta
what are the 2 types of CHOLINERGIC receptors
Nicotinic and Muscarinic
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Alpha 1
Vasoconstricin
Increased inotropy
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alpha 2
decreased SNS flow
NE release inhibited
Vasodilation
Decreased Chronotropy
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Beta 1
Increased Chronotropy
Increased Inotropy
Increased Dromotropy
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Beta 2
Increased inotropy
Increased Chronotropy
periphreal vasodilation
bronchodilation
works on pipes arteries and bronchi
what do Alpha antagonist do
interfere with the ability of catecholamines to provoke an alpha response
prevents effects of catecholamines on heart and vasculature
Inhbitory actin of epinephrine on insulin secretion
Main SE of alpha blockers
orthostatic hypotension
reflex tachycardia
impotence
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MOA r/t binding of the Aplha blockers
phentolamine, prazosin, and yohimbine
competative antagonist (reversiable
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MOA r/t binding with the alpha blocker Phenoxybenzamine
Covalently bonds
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4 ex of alpha antagonist
phentolamine
prazosin
yohimbine
Phenoxybenzamine
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which Alpha blocker is selective for alpha 1 receptors
Prazosin
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which Alpha blocker is selective for alpha 2 receptors
yohimbine
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which 2 alpha blockers are nonselective antagonist
phentolamine and
Phenoxybenzamine
phentolamin causes peripheral vasodilation and decreased B/p how fast? last how long
with in 2 min
10-15 min
what is the principle use for phentolamine
tx of acute htn emergencies such as introp manipulation of pheochromocytoma or autonomic hyperreflexia
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onset and duration of Phenoxybenamine
60 min
1/2 time 24 hours 9cumulative)
due to covalent bond
*****************clinical uses of phenoxybenzamine
pre-op control of bp in phenochromoctoma
excessive vasoconstriction in hemorrhagic shock
what is yohimbine used for
for rare pt with idiopathic orthostatic hypotensino
which Alpha blocker is less likely to cause reflex tachycardia
prazosin
Beta antogonist are derivative of what beta-agonist drug
isoproterenol
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which beta-adrenergic receptor antagonist is the only one cleared by plasma hydrolysis
Esmolol
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what are the onle 2 beta-adrenergic receptor antagonist
that have active metabolites
propranolol
acebutolol
what types of pts are selective B1 blockers good for and why
for asthma and COPDers
b/c it will save B2 effects
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which BB has rapid onset, is a short acting B 1 selective antagonist, and onlt administered IV
esmolol
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the full effect of esmolol is evident within how long?
and ceases after how long
5 min
10-30
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contraindications for BB
AV Blockheart failure
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what is teh drug of choice for massive BB overdose
and why?
Glucagon 1-10mg IV
bc it stimulates adecylate cyclase and increases intracellular cAMP
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Beta 2 receptor stimulation tends to facilitate the movement of what intracellularly
K+
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what drug is a Selective A-1 and non-selective B-1 and B-2 blocker
labetalol
************************with labetalol
the beta to alpha blocking potentcy is __:__ for oal and __:__ for IV
3: 1
7: 1
DONE
Bitches
I said done
Bitches
