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Flashcards in Autonomics Deck (112):
1

Mecamylamine mechanism

non-competitive antagonist of the nicotinic ganglionic receptors

2

Botulinum toxin type A mechanism

Inactivates SNAP25 inhibiting exocytosis

3

Muscarine mechanism

Muscarinic receptor agonist found in mushrooms

4

Atropine mechanism

Competitive antagonist for muscarinic receptors found in nightshade and jimson weed

5

Nicotine mechanism

Nicotinic receptor agonist

6

d-Turbocurare mechanism

Competitive antagonist for nicotinic receptors at NMJ

7

non-competitive antagonist of the nicotinic ganglionic receptors

Mecamylamine

8

Inactivates SNAP25 inhibiting exocytosis

Botulinum toxin type A

9

Muscarinic receptor agonist found in mushrooms

Muscarine

10

Competitive antagonist for muscarinic receptors found in nightshade and jimson weed

Atropine

11

Nicotinic receptor agonist

Nicotine

12

Competitive antagonist for nicotinic receptors at NMJ

d-Turbocurare

13

Preganglionic fibers exit from thoracic and lumbar regions of spinal chord

Sympathetic

14

Preganglionic fibers exit from cranial and sacral regions of CNS

Parasympathetic

15

Ganglia within CNS

Somatic

16

One efferent, myelinated nerve fiber from ganglia

Somatic

17

Denervation produces muscle atrophy

Somatic

18

Ganglia outside CNS

Autonomic

19

Two efferent non-myelinated nerve fibers

Autonomic

20

Two neurotransmitters of the autonomic nervous system

Norepinephrine and acetylcholine

21

Denervation revelats intrinsic tone

Autonomic

22

What is the primary site of drug action in the ANS

postganglionic nerves

23

What is the primary site of ANS integration into the CNS

hypothalmus

24

What is the CNS site of integration of cardiovascular reflexes and blood pressure control

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