Autonomics Flashcards
1
Q
Mecamylamine mechanism
A
non-competitive antagonist of the nicotinic ganglionic receptors
2
Q
Botulinum toxin type A mechanism
A
Inactivates SNAP25 inhibiting exocytosis
3
Q
Muscarine mechanism
A
Muscarinic receptor agonist found in mushrooms
4
Q
Atropine mechanism
A
Competitive antagonist for muscarinic receptors found in nightshade and jimson weed
5
Q
Nicotine mechanism
A
Nicotinic receptor agonist
6
Q
d-Turbocurare mechanism
A
Competitive antagonist for nicotinic receptors at NMJ
7
Q
non-competitive antagonist of the nicotinic ganglionic receptors
A
Mecamylamine
8
Q
Inactivates SNAP25 inhibiting exocytosis
A
Botulinum toxin type A
9
Q
Muscarinic receptor agonist found in mushrooms
A
Muscarine
10
Q
Competitive antagonist for muscarinic receptors found in nightshade and jimson weed
A
Atropine
11
Q
Nicotinic receptor agonist
A
Nicotine
12
Q
Competitive antagonist for nicotinic receptors at NMJ
A
d-Turbocurare
13
Q
Preganglionic fibers exit from thoracic and lumbar regions of spinal chord
A
Sympathetic
14
Q
Preganglionic fibers exit from cranial and sacral regions of CNS
A
Parasympathetic
15
Q
Ganglia within CNS
A
Somatic
16
Q
One efferent, myelinated nerve fiber from ganglia
A
Somatic
17
Q
Denervation produces muscle atrophy
A
Somatic
18
Q
Ganglia outside CNS
A
Autonomic
19
Q
Two efferent non-myelinated nerve fibers
A
Autonomic
20
Q
Two neurotransmitters of the autonomic nervous system
A
Norepinephrine and acetylcholine
21
Q
Denervation revelats intrinsic tone
A
Autonomic
22
Q
What is the primary site of drug action in the ANS
A
postganglionic nerves
23
Q
What is the primary site of ANS integration into the CNS
A
hypothalmus
24
Q
What is the CNS site of integration of cardiovascular reflexes and blood pressure control
A
medulla oblongata
25
ANS division with Discrete innervation
Parasympathetic
26
ANS division with diffuse innervation
Sympathetic
27
ANS division distributed to all tissues
Sympathetic
28
ANS division with chain ganglia
Sympathetic
29
ANS division with long pre-ganglionic fiber
Parasympathetic
30
The adrenal medulla is part of which ANS division
Sympathetic
31
What ANS division innervates the sweat glands? Which type of receptors are found there?
Sympathetic, Muscarinic
32
Name the receptor subtypes in the SA node of the heart which ANS division they belong to and the responses they illicit
M2, parasympathetic, decrease heart rate
| B1, sympathetic, increase heart rate
33
Name the receptor subtypes in the AV node of the heart which ANS division they belong to and the responses they illicit
M2, parasympathetic, decrease conduction velocity
| B1, sympathetic, conduction velocity
34
What is the SA node of the heart
the sinoatrial node is the impulse-generating (pacemaker) tissue located in the right atrium of the heart, and thus the generator of normal sinus rhythm.
35
What is the AV node of the heart
The atrioventricular node controls conduction velocity
36
Name the receptor subtypes in the atria and ventricles of the heart which ANS division they belong to and the respones they illicit
M2, parasympathetic, decrease contractility
| B1, sympathetic, increase contractility
37
Name the receptor subtypes in the blood vessels, which ANS division they belong to and the responses they illicit
Innervated by sympathetic only
Skeletal muscle-Alpha1 (Constriction), Beta2 (Dilation),
but contains M3 which constricts VSM, but causes NO release from endothelium resulting in dilation of VSM.
38
What occurs when MAP drops?
baroreceptors inactivate and there is increased sympathetic outflow
39
What occurs when MAP rises
baroreceptors activate increasing parasympathetic outflow.
40
What are the three tissues where sympathetic innervation is dominant
arterioles, veins, and sweat glands
41
What is the enzyme that synthesizes acetylcholine
Choline acetyl-transferase (CAT)
42
What two molecules are combined to create acetylcholine
Acetyl CoA and choline
43
What is the rate limiting step of acetylcholine synthesis
Transport of choline into nerve terminal by active transport
44
What are therapeutic uses of botulinum toxin type A
1) IM for muscle spasms/dystonias
2) Cosmetic
3) Intradermal for axillary hyperhidrosis (sweating)
4) Overactive bladder
45
Name the two enzymes that degrade acetylcholine
Acetylcholinesterase (AChE) and Butyrylcholinesterase
46
Name in order the intermediates in epinephrine synthesis
Tyrosine, Dopa, Dopamine, Norepinephrine
47
What is reserpine's MOA
irreversibly blocks VMAT-2 which depletes catecholamines from nerve terminals
48
Therapeutic use of reserpine
anti-hypertensive agent and antipsychotic
49
Side effects of reserpine
sedation, unopposed cholinergic effects (cramping, diarrhea), depression
50
Tyramine's MOA
displaces NE from vesicles leading to increased cytosolic concentrations and reversal of NE transporter actions
51
Where is tyramine found
In the diet. Aged cheeses, beer, wine, soy sauce, smoked meats, etc.
52
In what patients is tyramine a concern
Those taking MAOIs, since tyramine is normally degraded by MAO in the GI tract
53
Methyldopa's MOA
prodrug that is converted to methyl-NE and is an alpha-2 selective adrenergic receptor agonist. Since it does not stimulate the other receptors it is called a false transmitter. alpha-2 stimulation reduces sympathetic outflow from the CNS
54
Clinical use of methyldopa
oral antihypertensive agent that can be used safely during pregnancy
55
Side effects of methyldopa
sedation, dry mouth, parkinsonism and hyperlactinemia
56
Where are alpha-1 receptors and what response do they mediate
smooth muscle contraction
57
Where are alpha-2 receptors and what response do they mediate
Inhibitory response on nerves including presynaptic autoreceptors
58
Where are Beta-1 receptors and what response do they mediate
excitation of the heart, contraction of the kidney
59
Where are Beta-2 receptors and what response do they mediate
relaxation of the lung, skeletal muscle, vasculature, uterus.
60
What are two mechanisms of NE signal termination
neuronal re-uptake via NET
| Extraneuronal uptake by ENT
61
Cocaine's MOA
Inhibits NE reuptake, causes excess NE in the synapse
62
Name the two enzymes that metabolize catecholamines
MAO-mitochondrial, catechol-O-methyltransferase (COMT)- cytosolic (liver, kidney)
63
Only clinical use for acetylcholine
Wide angle glaucoma, contraction of the ciliary muscle opens trabelcular meshwork and increases outflow of aqueous humor
64
Do synthetic choline esters or cholinomimetic alkaloids penetrate the BBB
cholinomimetic alkaloids penetrate the BBB
65
bethanechol info
Synthetic choline ester
Prolonged effects, resistant to hydrolysis by cholinesterases
postop, postpartum urinary retention
GERD gastric atony
66
pilocarpine info
cholinomimetic alkaloid
Partial agonist of all muscarinic subtypes
Topical for wide-angle glaucoma
xerostomia (dry mouth)
67
cevimeline info
Cholinomimetic alkaloid
selective M3 agonist
Dry mouth for Sjogren's syndrome
Longer duration, fewer side effects than pilocarpine
68
Toxicity of muscarinic agonists
Sweating, hypotension, cramps, diarrhea
69
Contraindication of muscarinic agonists
hyperthyroidism (reflex tachycardia), asthma, peptic ulcer
70
Antidotes for muscarinic agonists
atropine and/or epinephrine
71
Atropine pharmokinetics
readily crosses BBB
72
What is the therapeutic indication for atropine?
Peptic ulcers
73
Name two reasons atropine is not a good drug for treating peptic ulcers
1. Toxicities at low doses (reduced secretions, mydriasis, cycloplegia, tachycardia, constipation, retention), therapeutic effect at high doses (10mg)
2. Only partially reduces gastric acid secretion
74
What is the effect of atropine on the CNS
mild excitation at low doses, toxic doses produce hallucinations and delirium resembling psychosis
(not present with scopolamine)
75
What are the ocular effects of atropine
mydriasis and photophobia, cycloplegia (paralysis of near vision)
76
What are the cardiovascular effects of atropine
Heart:
transient slowing due to blockade of M1 autoreceptors
tachycardia from blocking parasympathetic impulses
Circulation:
no effect at normal dose, flushing reaction by unknown mechanism
77
What are the respiratory effects of atropine
decrease bronchial secretions, relaxes bronchial smooth muscle
78
What are the GI effects of atropine
inhibits salvation, reduces motility and tone, partial reduction in gastric acid secretion
79
What are the 4 therapeutic uses of atropine
1. preoperative medication to reduce secretion
2. Bradycardia and AV block cardiac resuscitation
3. Mydriasis and cycloplegia (long duration)
4. Acetylcholinesterase inhibitor poisoning
80
Adverse effects of atropine
dry mouth, blurred vision, photophobia, tachycardia, GI distress (constipation), hot and dry skin
81
Contraindications for atropine
prostatic hypertrophy (trouble urinating), narrow-angle glaucoma
82
Atropine antidote
physostigmine, anti-cholinsterase
83
Drug interactions with atropine
drugs with anti-cholinergic side effects: antihistamines, phenothiazines, tricyclic antidepressants
84
Scopoamine info
muscarinic antagonist
better CNS penetration than atropine
sedative
can produce euphoria
suppresses emesis due to effect on vestibular apparatus
prophylatic patch for motion sickness and recovery from anesthesia
85
Ipratropium bromide info
muscarinic antagonist
| quaternary amine-does not cross membranes
86
Tropicamide
muscarinic antagonist
For diagnosis and surgery of ophthalmic disorders
mydriatic, cycloplegic
shorter duration (6 hrs) than atropine (7-12 d)
blurred vision and photophobia are side effects
87
Tolterodine
muscarinic antagonist for treatment of overactive bladder (urge incontinence)
unclear mechanism, only 30% effective
CNS-related anti-cholinergic effects, especially in elderly
88
Neostigmine
Anticholinesterase, only one that also acts as an angonist at NMJ nicotinic receptors. Therapeutically used for myasthenia gravis. Reversal of d-Turbocurarine poisoning. Post operative urinary retention.
89
Physostigmine
Anticholinesterase. Blood-brain permeable, mostly used for atropine poisoning.
90
Donepezil
Anticholinesterase. CNS selective, used to ameliorate Alzheimer's symptoms.
91
Malathion
Irreversible cholinesterase inhibitor. Nerve gas. Antidotes Atropine and Pralidoxime
92
Pralidoxime
reactivates AChE at NMJ, but must be done before aging occurs.
93
Features of catecholamine sympathomimetics
Not orally effective, short duration of action, does not cross BBB.
94
Features of non-catecholamine sympathomimetics
do not contain catechol functional group. orally effective, long duration of action, CNS effects
95
effects of alpha-1 activation
Vasoconstriction- homeostasis, decongestant, prolong anesthetics, blood pressure elevation
Mydriasis without cycloplegia (phenylephrine)
96
Effects of alpha-2 activation
CNS- reduces CNS sympathetic outflow
| Glaucoma- reduces intaocular pressure reduction of aqueous humor from cilliary body. (clonidine)
97
Effects of beta-1 activation
Increase cardiac output, treatment of shock (dobutamine)
98
Effects of beta-2 activation
Asthma and COPD, delay preterm labor (tertbutaline)
99
epinephrine receptor
all adrenergic receptors agonist
100
norepinephrine receptor
Alpa-1, Alpha-2, Beta-1 agonist
101
Isoproterenol receptor
Beta-2, Beta-2 agonist
102
Dopamine receptor
D1, B1, A1 agonist
103
Dobutamine receptor
B1 agonist
104
Phenylephrine receptor
A1 agonist
105
clonidine receptor
A2 agonist
106
terbutaline receptor
B2 agonist
107
Effect of alpha-1 blockade
reduced blood pressure, BPH, coldness of extremities
108
Beta-1 blockade
reduce blood presure, angia pectoris and MI, CHF and cardiac arrhythmias, decrase intaocular pressure, stage fright, migrane.
109
prazosin receptor
Alpha-1 antagonist
110
tamsulosin receptor
Alph-1a antagonist, used for BPH
111
Propranolol receptor
Beta-1,2 antagonist
112
Metapropol receptor
Beta-1 antagonist
