My Own Questions Flashcards
Potent… By IV administration, epinephrine induces peak response proportional to dose..
True
Factor/factors associated with characterizing blood pressure increases secondary to epinephrine administration:
Increase in blood pressure is due in ____
Increase in blood pressure is due in _____
Increased ventricular contractility (also known as a positive inotropic effect)
due in part to increased heart rate (also known as positive chronotropic effect)
T/FFollowing IV epinephrine administration,an increased blood pressure is observed in part because of drug-induced vasoconstriction, particularly in skin, mucosal, and renal precapillary resistance vessels.
True
T/F Following IV epinephrine administration, the pulse rate is initially increased but may then be decreased as a result of a compensatory cholinergic, vagal effect triggered by the baroreceptor reflex.
True
T/F Absorption of epinephrine following subcutaneous (s. c.) injection: slows result of local vasoconstrictor activity mediated by β receptor activation; if false why?
False; It is via ALPHA receptor
Administration of this agent by the intravenous infusion route is likely to cause an immediate reduction in pulse rate _____
norepinephrine
IV administration of this agent is LIKELY to result in an extended elevation in heart rate_______
ISOPROTERENOL
IV administration of this agent is MOST likely to induce both in elevation in systolic and diastolic pressure_____
Norepinephrine
IV administration of this agent is MOST likely to result in an extended elevation in vascular peripheral resistance_____
Norepinephrine
IV administration of this agent is MOST likely to cause the most profound decrease in diastolic blood pressure.
ISOPROTERENOL
IV administration of this agent is LEAST likely to cause an increase in systolic blood pressure
ISOPROTERENOL
IV administration of this agent is most likely to result in the most profound decrease in peripheral resistance______
ISOPROTERENOL
T/F At epinephrine doses that increased renal vascular resistance while having limited effects on mean arterial pressure renin secretion is increased.
True
T/F Epinephrine administration tends to increase arterial and venous pulmonary pressures.
True
T/F Factor(s) responsible for elevated pulmonary pressures due to epinephrine:
Direct pulmonary vasoconstriction
Redistribution of blood from the systemic circulation as a result of systemic vasoconstriction to the pulmonary circulation.
True Both
T/F Administration of high epinephrine concentrations may induce pulmonary edema secondary to high pulmonary capillary filtration pressure as well as possible effects on capillaries.
True
T/F Usually, under physiological circumstances, coronary blood flow:
Increased by epinephrine
Increased by cardiac sympathetic stimulation
True both
T/ F Epinephrine increases the slope of phase 4 depolarization, thus increasing heart rate.
True
Epinephrine on MYOCARDIAL SYSTOLE
- Systole is shorter/longer ?
- Systole exhibits increased contractility (more power)
- Cardiac output is increased
- Cardiac efficiency, described as work performed relative to oxygen consumed, is reduced..
shorter
Associated with higher doses of epinephrine administered:
PVCs
Ventricular Arrhythmias
T/F Epinephrine administration usually shortens the human AV nodal refractory.
True
β-adrenergic, non-selective blocker.
propranolol
Epinephrine-induced in ventricular arrhythmias: The likelihood of these arrhythmias may be enhanced as a result of reduced sinus rate and AV conduction secondary to increased vagal nerve activity.
reduced sinus rate and AV conduction secondary to increased vagal nerve activity.
Dependent on state of gestation, phase of sexual cycle and dose
Uterine Smooth muscle response to epinephrine
Epinephrine inhibits serotonin contraction during last month of pregnancy.
Epinephrine and bladder smooth muscle effect(s):
Detrusor muscle _____ _due to _____
_______of trigone and sphincter due to ______receptor
- Detrusor muscle relaxation due to β-adrenergic receptor activation.
- Contraction of trigone and sphincter muscle as a result of α-adrenergic receptor subtype activation.
Sympathetic effect is on radial muscle
Contraction
Autonomic effect: ciliary muscle of the eye:
Relaxation for far vision is the sympathetic-mediated response (β2)
Parasympathetic effect is contraction for near vision (M2, M3 muscarinic receptor subtype mediated)
T/F The parasympathetic action is to decrease conduction velocity and to promote blockade at the AV node.
True
The parasympathetic effect is the predominant action on which ORGAN
HEART
T/F The parasympathetic effect is to reduce contractility and decreased the action potential duration. With respect to contractility, the parasympathetic effect dominates.
True
Epinephrine beneficial effect(s) in asthma:
- Decreasing bronchial secretion
- Decreasing mucosal congestion
- Possible reduction in antigen-induced inflammatory mediator release from mast cells
- Direct bronchodilator effects
true
Inhibit insulins secretion
Alpha 2
Promote insulin secretion
Beta 2
T/F
The predominant effect of epinephrine with respect insulin secretion is mediated by activation of α2 receptors the activation of which inhibits insulin secretion.
T/F Epinephrine increases hematocrit
True
T/F Administration of epinephrine and selective β2 agonists tends increase physiological tremor.
True
Epinephrine effect(s) on plasma potassium:
- Epinephrine administration _______ plasma potassium.
- Epinephrine effects on plasma potassium are likely mediated by ______________________________
decreases; activation of β2 adrenergic receptors.
Epinephrine administered SYSTEMATICALLY result in substantial _______ and ________ activity.
sweating and pilomotor activity.
Very potent beta adrenergic receptor agonists with minimal effects on alpha adrenergic receptors:
ISOPROTERENOL
Sympathomimetic due to inhibition of transmitter uptake at noradrenergic synapses:
COCAINE
Beta-2 selective agonist– typically administered by aerosol for asthma management:
Albuterol
Beta-2 selective agonist– typically administered by aerosol for asthma management:
PHENTOLAMINE
Sympathomimetic drugs increase extracellular potassium
True
Effects of sympathomimetic agents on the gastrointestinal tract:
alpha -adrenergic receptor activation relaxes gastrointestinal smooth muscle
beta-adrenergic receptor activation relaxes gastrointestinal smooth muscle
alpha-2 agonists act indirectly by reducing acetylcholine release (presynaptic effect)
true
Catecholamine effects
Gq – protein coupling between beta-receptors and phospholipase C
alpha 1:most innervated vascular smooth muscle: contraction
? alpha 2:platelets: aggregation
? beta 2:uterine smooth muscle: smooth muscle relaxation
true
Rate-determining enzyme reaction in catecholamine biosynthesis
tyrosine hydroxylase
anatomical site for integration of autonomic information
Hypothalamus
Alpha receptor Blocker
PHENOXYBENZAMINE
Treat organophosphate and muscarinic intoxication
ATROPINE
Cholinergic activity on stomach acid secretions
INCREASED
DOMINANT AUTONOMIC TONE IN THE HEART
PARASYMPATHETIC
MULTIPLE USE OF SYMPATHOMIMETIC MAY LEAD TO
TACHYPHYLAXIS
NOREPINEPHRINE BLOCKER
PRAZOSIN
RATE LIMITING STEP IN CATECHLAMINE SYNTESIS
TYROXINE HYDROXYLASE
ENZYME CONVERTING DOPAMINE TO NOREPINEPHRINE
DOPAMINE BETA HYDROZYLASE
Norepinephrine to Epinephrine catalyzed by
Phenylethanolamine
N-Methyltransferase
Mediating pupillary dilation is
ALPHA-1
Primary receptor type at autonomic ganglia:
cholinergic: nicotinic
Preganglionic fibers terminating on adrenal medullary CHROMAFIN CELLS release
Acetylcholine
Rate-limiting step in acetylcholine synthesis:
Choline reuptake
Influx of this ion promotes fusion between axoplasmic membrane and nearby vesicles.
Calcium
Enzyme responsible for acetylcholine synthesis:
Choline acetyltransferase
Cholinergic receptor type that mediates the decrease in heart rate by activating potassium channels:
M2-muscarinic
Anticholinesterase agents used in antagonist-assisted neuromuscular-blockade reversal:
edrophonium
neostigmine
pyridostigmine
Muscarinic receptor activation: effects on cardiac currents
increase potassium conductance in atrial muscle, S.A., AV nodal tissue
(B) decreased inward calcium current
Cardiac muscarinic Type M2 receptor effects:
decreased phase 4 depolarization
B) decreased atrial contractility
C) decreased conduction velocity through the AV node
D) decreased ventricular contractility
Major of route of elimination for anticholinesterase drugs:
Answer: (C) renal
Quaternary ammonium compound; anticholinesterase – permanently positively charged:
NEOSTIGMINE
Dominant autonomic tone in the ventricle:
Adrenergic
T/F Atropine has limited effects on circulation because most vascular beds lack significant cholinergic innervation
True
T/F Anesthetic that probably increases central venous tone:
halothane
Factors influencing the speed and extent of neuromuscular-blockade reversal by anticholinesterases
Intensity of neuromuscular-blockade when reversal is initiated
(B) which nondepolarizing neuromuscular-blocking drug is being reversed
(C) hypothermia
(D) hypokalemia
(E) respiratory acidosis
Least effect on pupil size of all anticholinergic drugs used in preoperative medication:
glycopyrrolate
Anticholinesterase better for reversing atracurium blockade:
NEogstigmine
Effect of antimuscarinic agents on bronchiolar smooth muscle:
BRONCHORELAXATION
Arterioles – sympathetic: adrenergic
(C) gastrointestinal tract – parasympathetic: cholinergic
(D) veins – sympathetic: adrenergic
True
Correct order of adrenergic beta-agonist potency (greatest to least)
isoproterenol, epinephrine, norepinephrine
lpha receptor class activated by drugs such as clonidine:
alpha2
Enzyme(s) that degrade catecholamines:
(A) MAO (monoamine oxidase)
E) COMT (catechol-O-methyltransferase
Termination of norepinephrine effect is mainly due to:
reuptake into presynaptic nerve terminals
Competitive antagonist in both alpha1 and alpha2 receptor sites; also block serotonin receptors
Phentolamine
Alpha adrenergic antagonist more potent at alpha2 compared alpha1 adrenergic receptors:
yohimbine
Most abundant catecholamine in the adrenal medulla:
Epinephrine
Physiological consequences alpha-2 receptor activation:
increased vagal tone
decreased sympathetic outflow
Decreased insulin release
Order of alpha-adrenergic agonist potency (greatest to least):
Epinephrine, norepinephrine, isoproterenol
Rate-limiting step been catecholamine biosynthesis is catalyzed by this enzyme:
Tyrosine hydroxylase
Alpha-adrenergic receptors found primarily postsynaptically:
Alpha1
Miosis
Pilocarpine
Muscarinic agent: enhances transmission through the A-V node:
ATROPINE
Cholinergic receptor type primarily localized at skeletal muscle neuromuscular junctions:
Nicotinic
Cardiac muscarinic Type M2-receptor mediated action(s):
Decreased atrial and ventricular contractility
Ligand-gated ion channels:
NICOTINIC
Tends to cause fast responses:
MUSCARINIC
Cholinergic-receptor-mediated vasodilation – changes in intracellular concentration of this ion is principally responsible:
CALCIUM
Mechanism(s) of vasodilation mediated by the cholinergic system:
cholinergic activation promotes nitric oxide release from endothelial cells
? acetylcholine inhibits norepinephrine release from postganglionic sympathetic fibers
True
Major mechanism responsible for decreased AV nodal conduction following increased vagal tone:
Decrease in Calcium current in the AV node
Dominating autonomic tone in the ventricle:
SYMPATHETIC
Mechanisms by which muscarinic stimulation reduces ventricular contractility:
- reduces ventricular responds to norepinephrine
- reduces norepinephrine release from adrenergic terminals
True
Effect(s) of muscarinic agonists on the gastrointestinal and urinary tracts:
Increased intestinal peristalsis
increased tone
increased contraction amplitude
increase ureteral peristalsis
Substances that increase NO production
Substance P
Acetylcholine
Bradykinin
Major contraindications – muscarinic agonists
- asthma
- hyperthyroidism
- peptic ulcer
- coronary vascular disease
Probable cause of myasthenia gravis:
binding of anti-nicotinic receptor antibodies to the nicotinic cholinergic receptor
Drugs used for antagonist-assisted neuromuscular-blockade reversal
Tensilon
__________Produces postoperative analgesia without respiratory depression:
Intrathecal neostigmine (Prostigmin)
Preferred anticholinergic drug when sedation is the principal objective, preoperatively:
SCOPALAMINE
Mydriasis without loss of accommodation
SYMPATHOMIMETIC