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M1 FMK > ANS > Flashcards

ANS Flashcards

1
Q

Tonically active

A

There is continuous basal discharge along SNS and PNS nerves established by “pacemaker” neurons in the brainstem

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2
Q

ANS that has postganglionic cholinergic fibers

A

PNS

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3
Q

ANS that has postganglionic muscarinic receptors

A

PNS

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4
Q

Postganglionic neurotransmitters of PNS

A

ACh

Vasoactive intestinal peptide (VIP)

Nitric oxide (NO)

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5
Q

Postganglionic neurotransmitters of SNS

A

Epi and norepi

ATP

Neuropeptide Y (NPY)

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6
Q

Target cell types for SNS

SNS specific (no PNS)

A

Sweat glands and piloerector muscles

Liver, adipose, and kidney

Vascular smooth muscle

Lack PNS innervation

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7
Q

What target cells for both SNS and PNS

A

Smooth muscle

Cardiac muscle

Cardiac conducting tissue

Endocrine/exocrine glandular tissue

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8
Q

Physiologic competition between SNS/PNS and heart

A

PNS innervate only nodes of the heart - stimulation activates metabotropic AChR and slows HR

SNS innervate nodal cells of the heart, ventricular myocytes, and peripheral vasculature

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9
Q

Physiologic competition between SNS/PNS and lungs

A

PNS innervation activates metabotropic AChR’s that cause bronchoconstriction and mucous secretion

SNS activate metabotropic adrenergic receptors that induce bronchodilation

PNS - bronchoconstriction and secretions

SNS - bronchodilation

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10
Q

Physiologic competition between SNS/PNS and the eyes

A

PNS innervation activates metabotropic AChR’s that cause pupillary constriction and allow for accommodation (parasympathetics innervate the iris dilator muscle. Pupils constrict because the iris dilator contracts)

SNS innervation activates metabotropic adreneric receptors that cause pupillary dilation and has no effect on accomodation (SNS innervates the radial muscle - when contracted, the pupil is dilated)

Accomodation refers to the contraction of the ciliary muscles attached to the lens, which allows the lens to become more rounded - better able to focus on near objects (PNS control)

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11
Q

HR w/ and w/o PNS innervation

A

SA node w/ PNS drive - 60-100 bpm

SA node w/o PNS drive - 100-110 bpm (intrinsic automaticity of SA node)

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12
Q

Thermoregulatory (eccrine) sweat glands

A

Activated by ACh released by sympathetic nerves (exception to rule that sympathetic nerves are adrenergic)

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13
Q

ANS control of bladder function

A

Filling - SNS predominates (relaxation of detrusor m. and contraction of internal sphincter)

Micturition - PNS predominates (contraction of detrusor m. and relaxation of internal sphincter)

Dashed lines - sympathetic innervation Solid lines - parasympathetic innervation

α1 - in internal sphincter
β 2 , adrenoreceptor in detrusor muscle L1–L3, lumbar segments
M, muscarinic cholinoreceptor in detrusor muscle and internal sphincter S2–S4, sacral segments

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14
Q

Thoracolumbar outflow

A
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15
Q

Craniosacral outflow

A
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16
Q

MOA and target tissue of α 1 receptors

A
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17
Q

MOA and target tissues of α 2 receptors

A
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18
Q

MOA and target tissues of β 1 receptors

A
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19
Q

MOA and target tissues of β 2 receptors

A
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20
Q

MOA and target tissues of nicotinic receptors

A
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21
Q

MOA and target tissues of muscarinic tissues

A
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22
Q

Only type of agent that prevents accomodation of the eye?

A

PNS antagonist

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23
Q

All preganglionic neurons release ______, and all postganglionic neurons have ______ receptors

A

All preganglionic neurons release ACh and all postganglionic neurons have nicotinic AChR’s

no matter where we are in the body, everywhere and always within the autonomic nervous system, the first synapse from preganglionic to postganglionic tissue uses the neurotransmitter acetylcholine and i tgoes to a nicotinic acetylcholine receptor.

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24
Q

Does the PNS or SNS exit the spinal cord and form a trunk?

A

SNS forms a sympathetic trunk

PNS nerves stay separate

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25
Q

SNS innervation of adrenal medulla

A

Specialized sets of preganglionic SNS neurons do not synapse with a postganglionic neuron with a ganglion, but rather continue to the adrenal medulla where the medullary cells act as their ganglion.

The adrenal medullary cells have ACh receptors, just like a ganglionic neuron.

The cells of the adrenal medulla are neuroendocrine

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26
Q

Difference between epi/norepi and what receptors they bind

A

Epinephrine binds α1, α2, β1, and β2
Epi has access to β2; norepi
doesn’t.

β2 acts as sympathetic tone but also acts to check the norepi signal.

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27
Q

β2 receptor activation in vascular smooth muscle

A

Only activated by epinephrine - induces smooth muscle relaxation (all beta receptors raise cAMP in target tissues)

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28
Q

What causes constriction of smooth muscle arterioles?

A

Binding of norepinephrine onto alpha-1 receptors

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29
Q

β2 receptors in skeletal muscle only respond to what?

A

Circulating epinephrine (as opposed to direct innervation)

This is a delayed response relative to the sympathetic activation of alpha-1 receptors (vasoconstriction by binding of norepi) - alpha-1 receptors are also activated by circulating epi

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30
Q

What causes vasodilation in exercising muscle

A

Local metabolites and autoregulation

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31
Q

What is the response of skeletal muscle vasculature to sympathetic nerve stimulation?

A

Vasoconstriction

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32
Q

Rate and force of contraction of the heart

ANS control

A

β1 are the primary receptors and stimulation causes increase in both.

However, the dominant repsonse is cholinergic - causing decrease in both

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33
Q

Predominant tone of all blood vessels

A

Sympathetic

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34
Q

Predominant tone of bronchial tree

A

Parasympathetic

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35
Q

Muscarinic vs. nicotinic receptors

A
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36
Q

What enzyme converts norepinephrine to epinephrine?

A

Phenylethanolamine-N-methyltransferase

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37
Q

Enzymes that metabolize norepinephrine and terminate its actions

A

Monoamine oxidase and catechol-O-methyltransferase

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38
Q

NE biosynthesis

Diagram

A
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39
Q

Adrenergic receptors and their direct response

Diagram

A
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40
Q

All adrenergic receptors are ______, and activate through ______

A

All adrenergic receptors are metabotropic and activate through G proteins (Gi, Gs, Gq).

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41
Q
A

A) site 2

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42
Q

Atropine is a drug that is useful for dilating the pupil and it also paralyzes accommodation. These effects of atropine occur at which of the following sites on the diagram above (in question 1)?

A

D) Site 6

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43
Q

The flight or fight response is made possible by high levels of epinephrine circulating throughout the body, acting as a hormone, rather than a neurotransmitter. When acting at beta-2 receptors in the vasculature of skeletal muscle, what is the physiologic effect?

A

Vasodilation

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44
Q

Which enzyme is the rate-limiting step involved with synthesizing acetylcholine?

A

Choline acetyltransferase

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45
Q

M2 muscarinic receptors act via which second messenger pathways?

A

Decrease cAMP

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46
Q

ACh biosynthesis

A
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47
Q

Agonist and antagonist of nicotinic receptors

A

Agonist - ACh/Nicotine

Antagonist - Trimethaphan (Nn) only and curare (Nnmj) only

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48
Q

Agonist and antagonist of muscarinic recptors

A

Agonist - ACh and muscarine

Antagonist - atropine

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49
Q

Smooth muscle in vascular endothelium

Constriction of vessel diagram

A
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50
Q

Smooth muscle in vascular endothelium

Dilation of vessel diagram

A
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51
Q

Myocardial contractility

Diagram - MOA of norepi

A
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52
Q

Eccrine sweat glands involved in thermoregulation are innervated by what nerve fiber types?

A

Cholinergic postganglionic sympathetic fibers

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53
Q

Rapid activation of the sympathetic nervous system as in response to a fight or flight event (a lion walking into your backyard) will stimulate all of the following except one. Which is the exception?

A

Dilation of arterioles in skeletal muscle

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54
Q

The function of which of the following organs or systems is dominated by the sympathetic nervous system?

A

Systemic blood vessels

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55
Q

The odd muscarinic receptors (M1, M3, M5) primarily impact which second messenger pathway component?

A

Activate phospholipase C

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56
Q

What enzyme is the rate-limiting step in norepinephrine biosynthesis?

A

Tyrosine beta hydroxylase

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57
Q

Stimulation of which adrenergic receptor is associated w/ increased heart rate and increased myocardial contractility?

A

Beta 1 receptor stimulation

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58
Q

Which of the following is the common link inside vascular smooth muscle cells that is (a) activated when norepinephrine stimulates alpha 1 receptors and is (b) inhibited after epinephrine stimulates beta 2 receptors?

A

Myosin light chain kinase

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59
Q

If you administer a drug that blocks the nicotinic receptors in the ganglia, what do you expect will happen to heart rate?

A

The HR will increase

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60
Q

Steps between norepi binding to an alpha-1 receptor in smooth muscle vasculature and physiologic response of vasoconstriction

A
  1. Signal transduction through Gq
  2. Activation of phospholipase C
  3. Liberation of inositol triphosphate and diacylglycerol
  4. Intracellular calcium levels rise
  5. Calcium combines with calmodulin
  6. Myosin light chain kinase is activated
  7. Myosin becomes phosphorylated
  8. Actin and myosin interact
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61
Q

List steps between epi binding to a beta-2 receptor in smooth muscle of the lung and the physiologic response of bronchodilation

A
  1. Signal transduction through Gs
  2. Activation of adenylyl cyclase
  3. Formation of cAMP
  4. Activation of protein kinase A
  5. Phosphorylation of myosin light chain kinase
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62
Q

List the steps between norepi binding to a beta-1 receptor in heart and the physiologic response of tachycardia

A
  1. Signal transduction through Gs
  2. Activation of adenylyl cyclase
  3. Formation of cAMP
  4. Activation of protein kinase A
  5. Increased intracellular calcium levels
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63
Q

Biochemical function of alpha receptors

A

alpha-1 = phospholipase C activation, resulting in an increase in intracellular calcium

alpha-2 = inhibition of adenylyl cyclase, resulting in decreased cAMP

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64
Q

Physiological effect of alpha-1 receptor agonistic binding

A

Contraction of smooth muscles of urinary tract (bladder/prostate)

Exocrine gland secretion

Neuronal excitation

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65
Q

Physiological effect of alpha-2 receptor agonistic binding

A

Inhibition of norepinephrine release

Decrease in secretion of aqueous humor

Decrease in insulin secretion

Platelet aggregation

CNS effects (sedation)

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66
Q

Physiological effect of beta-1 receptor agonistic binding

A

Increase in secretion of renin

Increase in HR, contractility, and conduction

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67
Q

Physiological effect of beta-2 receptor agonistic binding

A

Glycogenolysis

Relaxation of smooth muscles

Uptake of potassium in skeletal muscles

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68
Q

Physiological effect of beta-3 receptor agonistic binding

A

Lipolysis

Thermogenesis

Relax detrusor

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69
Q

What are the biochemical effects of agonistic binding to beta-1 receptors?

A

Adenylyl cyclase activation - resulting in increased levels of cAMP and protein kinase A activation

Increases HR and contractility

Also increases secretion of renin

70
Q

What are the biochemical effects of agonistic binding to beta-2 receptors?

A

Adenylyl cyclase activation - resulting in increased levels of cAMP and protein kinase A activation

Beta-2 may also begin to couple go Gi in specific situations (i.e. HF)

71
Q

What are the biochemical effects of agonistic binding to beta-3 receptors?

A

Adenylyl cyclase activation - resulting in increased levels of cAMP and protein kinase A activation

Results in lipolysis

72
Q

Where are alpha-1 receptors usually found?

A

Smooth muscle

73
Q

Main targets of NE and epi at low doese

A

NE - alpha receptors

Epi - beta receptors

74
Q

What receptors are linked to Gq proteins?

A

Alpha-1 receptors

75
Q

What receptors are linked to Gi proteins?

A

Alpha-2 receptors (and sometimes beta-2)

76
Q

What adrenergic receptor class leads to cellular hyperpolarization upon agonistic binding?

A

Alpha-2 = linked to Gi - decreases cAMP and promotes efflux of K+

Often autoreceptors

77
Q

What adrenergic receptor class leads to vasoconstriction upon agonistic binding

A

Alpha-1 receptors are linked to Gq proteins - which increase Ca2+ levels inside cells, leading to contraction of smooth muscle

Also leads to release of neurotransmitters in neurons

78
Q

Midodrine

A

Alpha-1 agonist

Tx low BP in POTS

79
Q

Phenylephrine

A

Alpha-1 agonist

Causes rebound congestion (rhinitis medicamentosa) if used incorrectly due to tissue damage from poor blood flow

Phenylephrine can also be used as a vasopressor in emergencies to raise BP

80
Q

Agonistic binding of what adrenergic receptor causes mydriasis?

A

Agonistic binding of alpha-1 receptors causes pupil dilation by contracting the radial muscle

Alpha-1 increases phospholipase C activity which usually leads to contraction

81
Q

Direct-acting presynaptic alpha-2 agonists

List examples

A

Clonidine

Dexmedetomidine

Methyldopa

82
Q

Clonidine

A

Acts on alpha-2 autoreceptors

Inhibits further NE relase

Used as a 3rd or 4th line Tx fo hypertension and also for ADHD

Causes profound sedation

83
Q

Dexmedetomidine

A

Direct-acting presynaptic alpha-2 agonist

Often used during surgery or in ICU to provide sedation w/o causing respiratory depression

84
Q

Methyldopa

A

Prodrug - converted by dopa decarboxylase and dopamine beta-hydroxylase to a false neurotransmitter - alpha-methylnorepinephrine, which is stored inside vesicles

When neurons depolarize it is released - alpha-methylNE displaces dopamine and NE, acting as an agonist on alpha-2 presynaptic autoreceptors

Ultimately leads to less neurotransmitter release

Used in OB to Tx pregnancy-induced hypertension (pre-eclampsia) becuase of its safety profile

Ezymatic conversion occurs in neurons

85
Q

What drugs are used to reduce intraocular pressure by decreasing the production of aqueous humor and increasing its drainage?

A

Alpha-2 agonists:

Brimonidine or apraclonidine

86
Q

Ephedrine

A

Indirect-acting sympathomimetic

Stimulates release of catecholamines from nerve terminals

Relatively resistant to MAO and COMT

Also pseudoephedrine

87
Q

Tyramine

A

Indirect-acting sympathomimetic

Found in food

Stimulates release of pre-formed catecholamines

Normally degraded rapidly by MAO in gut - hypertensive crisis when MAO is compromised

88
Q

What indirect-acting sympathomimetic inhibits norepinephrine reuptake transporters?

A

Cocaine bitch

89
Q

What indirect-acting sympathomimetic causes reverse transport of norepi/dopamine out through the reuptake transporters?

A

Amphetamine/Methylphenidate

90
Q

Phentolamine

A

Non-selective alpha antagonist (block both alpha-1 and 2)

Short-acting and reversible blocker (name is shorter than other non-selective alpha antagonist)

Administered IV

91
Q

Phenoxybenzamine

A

Non-selective alpha antagonist

Long-acting and irreversible blocker

Administered orally

92
Q

What drugs block the effects of epinephrine, and when would it be pertinent to do so?

A

Phentolamine and phenoxybenzamine are both non-selective alpha antagonists

They are used primarily to Tx Pt’s w/ pheochromocytoma (adrenal tumor that releases excess catecholamines) - especially important during surgery - where manipulation of the tumor can release epi

Also used to Tx Pt’s w/ frostbite: IV phentolamine vasodilates quickly to restore perfusion

93
Q

Selective alpha-1 antagonists

A

Prazosin/doxazosin/terzosin - vasodilation (3rd/4th line antihypertensives due to side-effects)

Side-effects:

First-dose syncope (esp. Pt’s that are dehydrates or sodium-deplete [diuretics], due to sudden venous pooling)

Reflex tachycardia due to baroreceptor activation as BP drops

Miosis - pupillary constriction

Tamsulosin/alfuzosin/sildosin - Tx BPH and have greater selectivity for alpha-1 receptors in prostate gland

93
Q

Where are beta-1 receptors primarily found?

A

Heart and kidneys

93
Q

Where are beta-2 receptors primarily found?

A

Lungs, blood vessels, and smooth muscles (i.e. the uterus)

94
Q
A
95
Q

Baroreceptors

A

Pressure-sensors in the carotids and aortic arch

Send signal to the ventrolateral medulla, nucleus of the solitary tract - activate the sympathetic nervous system to raise HR and BP

Selective alpha-1 antagonist can trigger reflex tachycardia (TPR decreases - increasing CO w/ increase in HR)

96
Q

What happens to heart rate when phenylephrine is infused?

A

HR decreases

97
Q

What is the mechanism of pseudoephedrine?

A

Promote release of preformed catecholamines

98
Q

Which G protein do alpha-2 receptors couple to?

A

Alpha-2 receptors couple to Gi proteins

99
Q

Give an example of a cardioselective antihypertensive

A

Metoprolol

100
Q

Clonidine and methyldopa share some similarities in terms of actions at which of the following receptors?

A

Alpha 2

101
Q

What drugs cause reflex tachycardia?

A

Drugs that induce vasodilation - alpha-1 antagonists and beta-2 agonists

102
Q

When NE is administered after pre-Tx w/ atropine (prototypical muscarinic receptor antagonist) what is the response in HR?

A

Increase in HR caused by direct cardiac action

103
Q

A possible effect of administering a beta-2 agonist to a patient is?

A

C. Skeletal muscle tremor

104
Q

A possible effect of administering a beta-1 agonist to a patient is?

A

A. Direct stimulation of renin release

105
Q

Pindolol

A

Partial beta-1 and 2 agonist (intrinsic sympathomimetic activity) - does not slow HR as much as a pure antagonist

106
Q

Which of the following produces the traces shown in B?

A. Epi
B. Isoproterenol
C. Norepi

A

Epinephrine is associated with trace B

Norepinephrine is associated with trace A

Isoproterenol is associated with trace C

107
Q

M1, M3, and M5 muscarinic receptors

A

Are linked to Gq proteins, which generally cause smooth muscle contraction

108
Q

M2 and M4 muscarinic receptors

A

Linked to Gi proteins, which usually inhibit cells by hyperpolarizing them

109
Q

Where are M1 receptors found?

A

In nerves

110
Q

Where are M2 receptors found?

A

Primarily the heart

111
Q

Where are M3 receptors found?

A

They are found in glands, smooth muscle of the lungs and bladder, blood vessels, and the eye

112
Q

Where are M4 and M5 receptors found?

A

Mainly in the CNS

113
Q

Ng (aka Nn) receptors

A

Nicotinic receptors found in nicotinic ganglia

Ng = nicotinic ganglia

Nn = nicotinic neuronal receptors

114
Q

How do indirect-acting muscarinic agonists work?

A

By inhibiting acetylcholinesterase (AChE) - breaks down ACh

Allows more ACh to remain in synapse, increasing stimulation of both muscarinic and nicotinic receptors

115
Q

Muscarinic agonist effects

A

Mnemonic: SLUD + Miosis

Salivation
Lacrimation
Urination
Defecation

Other effects: hypotension (due to vasodilation), and bronchoconstriction

116
Q

Three main classes of indirect-acting cholinergic agonists

A
  1. Alcohols (i.e. edrophonium): Bind to AChE and are rapidly broken down by hydrolysis
  2. Carbamates (i.e. pyridostigmine, physostigmine, neostigmine): Bind to AChE and are broken down more slowly than alcohols
  3. Organophosphates (i.e. echothiophate, insecticides, nerve gases): Bind to AChE and hdryolyze very slowly or form covalent bonds with the enzyme
117
Q

Pralidoxime

A

Used to treat organophosphate poisoning - to regenerate AChE - only works if Tx is given before aging occurs

Aging - the formation of covalent bond to AChE

118
Q

Muscarinic receptor antagonist

A
  1. Red as a beet
  2. Dry as a bone
  3. Blind as a bat
  4. Mad as a hatter
  5. Block sweating - causes flushing
  6. Reduced secretions (saliva/mucous) - dry mouth/skin
  7. Impair visions by blocking accomodation (focusing close up)
  8. In higher doses - confusion or delerium
119
Q

Muscarinic antagonist used to treat bradycardia

A

Atropine

120
Q

Muscarinic antagonist used to treat athma/COPD

A

Drugs like ipratopium and tiotropium block M3 receptors in the lungs - bronchodilation and decreased mucus production

121
Q

Muscarinic antagonist used to treat diarrhea/IBS

A

Drugs like dicyclomine - slow down GI motility and reduce cramping

122
Q

Muscarinic antagonist used to treat overactive bladder

A

Drugs like oxybutynin - block contractions of the detrusor

123
Q

Muscarinic antagonist used to treat motion sickness

A

The scopolamine patch - blocks ACh in the brain’s vomiting center

124
Q

What conditions do muscarinic antagonists worsen?

A

Cognitive decline in the elderly - esp. Alzheimer’s or dementia

Hyperthermia - antimuscarinics prevent sweating

125
Q

Muscarinic antagonists effects on the eyes

A

Mydriasis (pupil dilation due to relaxation of the iris sphincter (tropicamide dilates pupil)

Dry eyes

Worsening of glaucoma - they reduce aqeous humor outflow and can increase intraocular pressure (contraindicated in Pt’s w/ angle-closure glaucoma)

Cycloplegia (loss of accomodation due to relaxation of the ciliary muscle which causes the lens to flatten)

126
Q

Varenicline

A

Partial agonist/antagonist at nicotonic receptors - helping satisfy cravings while simultaneously blocking full effects of nicotine

127
Q

Nicotinic Antagonists

A

Neuromuscular junction blockers: succinylcholine (depolarizing blocker)

Non-depolarizing blockers (Curare derivatives): atracurium, rocuronium, vecuronium

128
Q

Succinylcholine

A

Initially activates nicotinic receptors (Nnmj) causing Na+ to influx, depolarizing the cell and resulting in muscle contraction (fasciculations). However, it stays bound to the receptor, preventing repolarization, which leads to prolonged muscle paralysis

Adverse effects: hyperkalemia and malignant hyperthermia (Tx with dantrolene - prevents Ca2+ from SR)

Short duration of action (~8 min.) and is metabolized by plasma cholinesterase (aka butrylcholinesterase)

129
Q

Competitive antagonists at the Nnmj

A

Atracurium, rocuronium, and vecuronium are non-depolarizing Nnmr blockers

~25-120 min duration (depends on drug)

Indirect-acting muscarinic agonists can be administered to increase the level of ACh in the synapse

130
Q
A

B. Neuromuscular end-plate

131
Q
A

A. Increase bladder tone

132
Q
A

B. M3

133
Q
A

D. Both may increase GI motility

134
Q
A

C. Increase GI motility

135
Q
A

B. Increased cardiac rate

136
Q
A

Physostigmine

137
Q
A

A. Increased intraocular pressure

138
Q

Receptor specificity of bethanecol

A

Muscarinic

Used for GI and urinary stimulation

139
Q

Receptor specificity for carbachol

A

Muscarinic and nicotinic receptors

Used to induce miosis during ophthalmic surger

140
Q

Receptor specificity for pilocarpine

A

Muscarinic receptors

Applied topically to the eye to Tx glaucoma (lowers intraocular pressure)

Also oral Tx for xerostomia (dry mouth)

Side effect: decrased night vision caused by miosis and difficulty focusing on distant objects (lens is accomodated for near vision)

141
Q

Why don’t choline esters distribute to the CNS?

A

They contain a quartenary ammonium derivative

142
Q

Cevimeline

A

Muscarinic agonist to Tx dry mouth

143
Q

What drug is used to Dx myasthenia gravis?

A

Edrophonium IV

144
Q

Echothiophate

A

Applied topically to the eye to Tx glaucoma and accommodative estropia (binds to cholinesterase quasi-reversibly)

Miosis
Contracts ciliary muscle (improves focus through “spasm of accommodation”)

145
Q

MOA of acetylcholinesterase hydrolyzing acetylcholine

A
146
Q

MOA of acetylcholinesterase hydrolyzing neostigmine

A
147
Q

What type of receptors are the nicotinic receptors found at the ganglia?

A

Ionotropic

148
Q

Which of the following is a depolarizing nicotinic receptor blocker?

A

Succinylcholine

149
Q

What is the site of action of vecuronium

A

Nicotinic receptors at the neuromuscular junction (Nnmj)

Competitive Zach antagonist

150
Q

Which of the following is used as an antidote for organophosphate poisoning?

A

Praladoxime

151
Q

MOA of scopolamine

A
152
Q

MOA of bethanechol

A

Muscarinic receptor agonist

GI and urinary stimulation

153
Q

MOA of atropine

A

Muscarinic receptor antagonist

Increase HR

154
Q

MOA of neostigmine

A

Acetylcholinesterase inhibitor

155
Q

Muscarinic receptor agonist effect on the eye

A
156
Q

Muscarinic receptor antagonist effect on the eye

A
157
Q

When is norepi used

A

To Tx warm shock: when BP is low and HR is high; mainly used clinically as a vasopressor

158
Q

When is epi used

A

When BP is high and HR is low (cold shock); used for anaphylaxis to bronchodilate, increase HR, and vasoconstrict to counteract widespread vasodilatio; ACLS to stimulate heart; bronchospask

159
Q

When is isoproterenol used

A

To increase myocardial contractility (i.e. decompennsated heart failure, cardiogenic shock)

160
Q

Cycloplegia

A

Paralysis of accomodation due to relaxation of the ciliary muscle (cannot see up close, only far away)

Physiologic consequence of anti-muscarinics

161
Q

Antimuscarinic effect on intraocular pressure (IOP)?

A

Increases IOP

162
Q

-olol drug effects on the eye

A

Beta blockers decrease the production of aqueous humor

163
Q

Why Dx myasthenia gravis w/ IV atropine and edrophonium

A

Atropine - antimuscarinic

Edrophonium - acetylcholinesterase inhibitor

Blocking - SLUD syndrome with atropine

164
Q

What is used IV to reverse muscle paralysis?

A

Neostigmine

165
Q

What is the drug used for maintenance of myasthenia gravis?

A

Pyridostigmine

Cholinergic crisis is common during initial Tx - too much stimulation of Nnmj receptors does not allow for repolarization

166
Q

What type of drug (class) is used to Tx urinary retention?

A

Muscarinic receptor agonist

167
Q

Which of the following drugs is used to Tx open-angle glaucoma and has a side-effect profile of: difficulty with far vision and problems seeing in dim light.

A. Pilocarpine
B. Timolol
C. Apraclonidine
D. Epinephrine
E. Phenylephrine

A

A. Pilocarpine

Pilocarpine is a muscarinic receptor agonist

Pilocarpine causes the ciliary muscle to contract, which increases tension on the scleral spur and opens the trabecular meshwork. This allows aqueous humor to drain from the eye, which decreases intraocular pressure while also decreasing one’s ability for far vision.

168
Q

What type of receptors control sweat glands and what are they innervated by?

A

The SNS innervates M3 receptors at sweat glands

169
Q

When pupillary dilation but not cycloplegia is desired, the best drug to use would be a drug that has a similar MOA as which of the following?

A. Isoproteronol
B. Phenylephrine
C. Pilocarpine
D. Tropicamide

A

B. Phenylephrine

Alpha-1 agonist will produce mydriasis without cycloplegia. Cholinergic antagonist drugs will also produce pupil dilation along with cycloplegia.

M1 FMK (55 decks)

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