Sem 2 Block 1 Flashcards
1
Q
muscarinic receptors are __
nicotinic receptors are __
GPCR vs ligand gated
A
muscarinic= GPCR
nicotinic= ligand gated
2
Q
what is the result of muscarinic receptor binding
A
formation of IP3= increased intracellular calcium
3
Q
what is the result of nicotinic receptor binding
A
opening of Na+ and K+ channels leading to depolarization
4
Q
are somatic motor neurons cholinergic or adrenergic
A
cholinergic
5
Q
what is the effect of the drug hemicholinium
A
inhibit choline carrier
6
Q
what is the effect of the drug vesamicol
A
inhibition of vesicle associated transporter
7
Q
what is the effect of botulinum toxin
A
inhibition of release of acetylcholine by inhibiting specific SNARE proteins required for exocytosis
8
Q
what is the effect of neostigmine
A
it’s an antiacetylcholinesterase which as a result, increases ACh at the neuromuscular junction
9
Q
M1 and M3 are what class of GPCR
A
Gq= increases phospholipase C= increase IP3= increase Ca2+
10
Q
M2 is what class of GPCR
A
Gi= decreases adenyly cyclase= decreased cAMP
11
Q
muscarinic receptors are blocked by __
A
atropine
12
Q
gastric glands have M_ receptors while the rest of the GIT has M_
A
gastric glands= M1
rest= M3
13
Q
parasympathetics have the greatest effect on M2 receptors at what location of the heart
A
SA and AV node
14
Q
what are the 2 classes of cholinesterases
A
acetyl cholinesterase= true
butyryl cholinesterase= pseudo
15
Q
what is the difference in function between acetyl cholinesterase and butyryl cholinesterase
A
acetyl= termination of ACh action
butyryl= hydrolysis of ingested esters
16
Q
in the cardiovascular system, ACh activates __ receptors on vascular endothelium resulting in the production of __ which causes __
A
M3
NO/endothelial derived growth factor
vasodilation
17
Q
ACh with muscarinic receptors causes increased tone and peristalsis through M_ and increased secretions of the GIT glands through M_
A
M3
M1
18
Q
dilator pupillae has what sympathetic receptor
A
alpha1
19
Q
sphincter pupillae has what parasympathetic receptor
A
M3
20
Q
what adrenergic sympathetic receptor is found on the ciliary muscle
A
beta2
21
Q
what is the difference between miosis and mydriasis
A
miosis= pupil constriction
mydriasis= pupil dilation
22
Q
what is the effect of pupil contraction on intraocular pressure
A
intraocular pressure decreases (there is increased access to the trabecular network)
23
Q
contraction of what muscle allows for near vision by making the suspensory ligaments loose
A
ciliary muscle
24
Q
ACh causes contraction of the circular muscle of the iris leading to widening of the iridocorneal angle. this __ outflow of aqueous humor and __ intraocular pression
A
increased outflow
decreases intraocular pressure
25
what is the effect of mydriasis on aqueous humor flow
mydriasis narrows the iridocorneal angle, blocking the passage of aqueous humor from the posterior chamber to the anterior chamber
26
voiding of urine can occur as muscarinic agonists cause contraction of __ and relaxation of __
contract detrusor (M3)
relax trigone/internal sphincter
27
besides acetylcholine, what are 2 examples of a choline ester
bethanechol
carbachol
28
bethanechol primarily affects what 2 tracts
urinary
GI
29
bethanechol stimulates atonic bladder (bladder muscles don't fully contract), particularly in what 4 situations
post-partum
post-operative
non-obstructive urinary retention
megacolon
30
what is carbachol, a cholinergic drug, used for
topically in the eye as a miotic agent to treat glaucoma
31
what is the methacholine challenge test used to diagnose
bronchial asthma
32
what are some adverse effects of cholinergic drugs such as bethanechol and carbachol
flushing, sweating, decreased BP, abdominal pain, diarrhea, bronchospasms
33
what type of receptor does cevimeline activate
M3 receptors on lacrimal and salivatory glands
34
what is pilocarpine used for
pupil constriction for emergency lowering of intraocular pressure
35
are neostigmine and physostigmine direct or indirect acting cholinergic drugs
indirect
36
are neostigmine and physostigmine reversible or irreversible acting cholinergic drugs
reversible
37
acetylcholinesterase hydrolyzes ACh very rapidly in 2 steps. these steps are
1. initial step
acetylcholine-_>choline+acetylated AChE
2. hydrolysis
acetylated AChE+H2O -->AChE+acetate
38
what is the effect of neostigmine and physostigmine on AChE and the rate of drug-enzyme complex hydrolysis
there is temporary inhibition of AChE
drug enzyme complex is freed at a slower rate
39
is physostigmine, an indirect reversible AChE inhibitor:
charged or uncharged
lipid or water soluble
cross or doesn't cross BBB
uncharged
lipid soluble
cross BBB
40
what reversible AChE inhibitor is used to treat atropine overdose
physostigmine
it crosses the BBB so it has an effect on the CNS and PNS
41
can neostigmine, a reversible AChE inhibitor be used to reverse CNS effects, why
no, it doesn't cross the BBB
42
what AChE inhibitor drug is used to treat myasthenia gravis, paralytic ileus, and urinary retention
neostigmine
43
what drug is used in the Tensilon test
edrophonium
44
what drug is used in the Tensilon test
edrophonium
45
what is the Tensilon test with endrophonium used for
to differentiate a cholinergic crisis from a myasthenic crisis
46
how does a cholinergic crisis differ from a myasthenia crisis
cholinergic crisis- overdose of AChE inhibitor
myasthenia- acute exacerbation of the disease
47
the Tensilon test can either improve or worsen symptoms. which tells of a myasthenia crisis vs a cholinergic crisis
myasthenia= improvement of symptoms
cholinergic= worsening of symptoms
48
what drug class is used for postoperative decurarization
AChE inhibitor
49
are organophosphate compounds:
direct or indirect acting
reversible or irreversible
indirect
irreversible
50
what is the treatment for organophosphate poisoning
organophosphates are an AChE inhibitor= increased ACh= increased parasympathetic activity
administration of atropine= blockage of muscarinic receptors= decreased parasympathetic activity= atropinized= pupils dilate (reverse of muscarinic activity)
pralidoxime reverses the nicotinic receptor effects
51
what is the function of palidoxime
oximes bind to free AChE allowing it to act as an AChE inhibitor
52
what is the effect of atropine
blocks muscarinic drugs competitively centrally and peripherally
53
does atropine cross the BBB
yes
54
what are 2 examples of natural alkaloid antimuscarinic drugs
atropine
scopolamine (Hyoscine)
55
what are 2 synthetic antimuscarinic drugs which are used for ophthalmic practice to dilate eyes in the short term
cyclopentolate
tropicamide
56
what is the main action of atropine on the cardiovascular system
tachycardia
57
why does atropine not affect blood pressure
sympathetic is dominant in vasculature
histamine caused vasodilation
atropine causes vasodilation
58
what is the cause of atropine flush
release of histamine dilates cutaneous blood vessels
59
what are 2 antimuscarinic drugs are used in ophthalmology due to their short acting duration
cyclopentolate
tropicamide
60
what is the effect of atropine on body temperature
increased body temp leading to atropine fever
61
what medication is used for motion sickness
scopolamine
62
what is one of the adverse effects of scopolamine
it causes euphoria so it is subject to abuse
63
what is the effect of using phenylephrine for funduscopic exam
it produced a short lasting mydriasis without cycloplegia
64
atropine is contradicted for what 2 condition
peptic ulcer disease
glaucoma
65
traveler's diarrhea is treated with what 2 drugs, why combined
atropine and diphenoxylate
atropine is added for it's side effects to prevent addiction to the diphenoxylate opioid
66
what are the 4 classes of skeletal muscle relaxants
competitive (non-depolarizing)
non-competitive (depolarizing)
direct acting
centrally acting
67
what are the main class of non-depolarizing skeletal muscle relaxanta
curare (-curonium)
68
what is the main class of depolarizing (non-competitive) skeletal muscle relaxants
succinylcholine
69
what are the 3 main classes of centrally acting skeletal muscle relaxants
benzodiazepines
GABA derivatives
alpha2 agonist
70
what drug acts as an antagonist to non-depolarizing competitive skeletal muscle blockers
neostigmine
71
how do curare drugs produce a fall in BP, flushing, and bronchoconstriction
they release histamine and ganglionic blocking activity
72
since succinylcholine, a depolarizing (non-competitive) skeletal muscle relaxant, does not dissociate rapidly from the receptor, what is the effect
prolonged depolarization
inactivation of Na+ channels
ACh is unable to generate AP
73
what enzyme metabolizes succinylcholine
pseudocholinesterase
74
what is an adverse effect of atracurium
it's metabolite (Laudanosine) can cause seizures
75
what are the 3 main side effects of succinylcholine
hyperkalemia
malignant hyperthermia
prolonged apnea
76
what patients is scoline apnea seen in
those who are genetically deficient in plasma cholinesterase or have an atypical form of plasma cholinesterase
77
succinylcholine is contradicted in patients with what 2 conditions
atypical pseudocholinesterase
malignant hyperthermia
78
what drug can be given to overcome competitive non-depolarizing skeletal muscle relaxants
cholinesterase inhibitors such as neostigmine
79
what is an example pf a direct acting skeletal muscle relaxant
dantrolene
80
how does the direct acting skeletal muscle relaxant dantrolene work
it blocks ryanodine receptors which causes a reduction/block in calcium release, leading to skeletal muscle relaxation
81
how does baclofen work as a central skeletal muscle relaxant
it activates GABA b receptors leading to skeletal muscle relaxation
82
what is the difference between central and peripheral skeletal muscle relaxants
central- inhibit polysynaptic reflexes in the CNS
peripheral- clock neuromuscular transmission
83
what is the difference between central and peripheral skeletal muscle relaxants in terms of uses
central- chronic spastic conditions
peripheral- short surgical procedures
84
ganglionic blockers act on what receptor
they're competitive antagonists at Nn, reducing parasympathetics
85
ganglion blockers are similar to the effect of atropine except in what 2 sites
sweat glands
blood vessels
86
what drug will block the reflex bradycardia that occurs when phenylephrine or other vasopressors cause vasoconstriction
hexamethonium (a ganglion blocker)
87
what drug interferes with the synthesis of catecholamines by inhibiting tyrosine hydroxylase
metyrosine
88
what drug blocks the storage of catecholamines in granule or granular uptake by inhibiting vesicular monoamine transporter (VMAT) into vesicles
reserpine
89
what 2 drugs cause displacement of catecholamines from vesicles, causing their release
amphetamine
tyramine
90
what 2 drugs prevent the release of catecholamines from adrenergic terminals
bretylium
guanethidine
91
what 2 drugs block the reuptake of catecholamines at the nerve terminal
cocaine
imipramine
92
how does the metabolism of norepinephrine differ from serotonin
norepinephrine is metabolized by MAO then COMT
serotonin is metabolized by MAO only
93
what is the effect of alpha2 receptor activation in the pancreas
decrease insulin secretion
94
what is the affect of alpha2 receptor activation on platelets
aggregation
95
what is the effect of beta2 activation on the uteru
relaxation
96
what is the effect of beta2 activation on the uterus
relaxation
97
what adrenergic receptor is found on adipose tissue to increase lipolysis
beta3
98
alpha1 receptors use what G protein, what is the effect
Gq
IP3/Ca2+
99
alpha2 receptors use what G protein, what is the effect
Gi
decrease cAMP
100
beta and dopamine receptors use what G protein, what is the effect
Gs
increase cAMP
101
what are 2 examples of alpha1 receptor selective antagonists
phenylephrine
methoxamine
102
what is an example of an alpha1 receptor selective antagonist
prazosin
103
what is an example of an alpha2 receptor selective agonist
clonidine
104
what is an example of a beta1 receptor selective agonist
dobutamine
105
what are 2 examples of beta1 receptor selective antagonists
atenolol
metoprolol
106
what are 2 examples of beta2 receptor selective agonists
albuterol
terbutaline
107
are alpha or beta receptors more sensitive to activators at a low dose
beta
108
are alpha or beta receptors more sensitive to activators at a high dose
alpha
109
epinephrine uses what receptors
all (alpha and beta)
110
norepinephrine uses what receptors
all except B2 (uses alpha1, alpha2, and beta1)
111
isoproterenol uses what receptors
beta only (beta1 and beta2)
112
dobutamine uses what receptors
only beta1
113
pulse pressure increases due to stimulation of what receptor
beta1
114
why don't alpha1 receptors change pulse pressure
they increase both systolic and diastolic pressure
115
what receptor stimulation increases systolic pressure
beta1
116
what receptor stimulation decreases TPR and diastolic pressure
beta2
117
does epinephrine or norepinephrine show a biphasic response in which there are different effects based on dose
epinephrine
118
what is the biphasic response seen with norepinephrine
epinephrine at low dose acts on beta2 receptors-->vasodilation
epinephrine at high dose acts on alpha1 receptors-->vasoconstriction
119
after an alpha receptor block, there is reflex tachycardia in which heart rate is greater then what it was before the alpha blockade. why?
decrease in blood pressure with beta receptor activity increases RVLM activity which causes secretion of norepinephrine
120
does epinephrine cause hypo or hyperglycermia
hyperglycemia
(there is an increase in glycogenolysis and gluconeogenesis)
121
what is the effect of epinephrine on aqueous humor production
reduces production due to vasoconstriction and enhanced aqueous humor flow
122
what is the drug of choice for anaphylactic shock
epinephrine
123
epinephrine use is contradicted in what health condition
angina pectoris
124
norepinephrine has no effect on what receptors
beta2
125
does norepinephrine increase systolic pressure, diastolic pressure, or both
both
126
isoproterenol has no effect on what receptors
alpha
127
what drug is used to increase GFR, renal blood flow, and Na+ excretion to prevent kidney failure in cases of septic shock
low dose dopamine
128
high dose of dopamine stimulates alpha1 receptors leading to vaso__
vasoconstriction
