Pharmacology Class 2020: Adrenergics Flashcards
Where does the preganglionic neuron originate within the autonomic nervous system?
CNS Adrenal Medulla
what two neurons are required to reach a target organ within the autonomic nervous system?
preganglionic
postganglionic
What part of the body is the sympathetic nervous system originate?
thoracolumbar
Does the sympathetic nervous system have long or short postganglionic fibers?
Long
Is the sympathetic nervous system anabolic or catabolic?
catabolic
The parasympathetic nervous system is a catabolic system.
True or False
False
Anabolic
What part of the body does the parasympathetic nervous system originate from?
craniosacral
Are the fibers within the parasympathetic nervous system long or short?
short fibers
Where does NE originate from within the CNS?
adrenergic nerve endings in the brain
Where is Epi released from within the body?
Adrenal Medulla and acts as a hormone
Drugs that mimic the actions of Epi and NE
Sympathomimetic
What is the immediate precursor to NE
Dopamine
What are Epi and NE classified as
Catecholamines
What molecule are catacholamines derived from?
Tyrosine AA
What is the mechanism of tyrosine conversion to dopamine?
Tyrosine is converted to dopamine through the rate limiting step of hydroxylation of tyrosine and its transport into a vesicle.
The transportation of tyrosine into the vesicle to create dopamine is inhibited by what drug?
Reserpine
What is required for the release of NE within the vesicle at the adrenergic receptor?
The influx of Calcium to cause the infusion of the vesicle with the membrane in a process called exocytosis.
What is the process of the fusion of the vesicle with the membrane?
exocytosis mediated by influx of calcium
What blocks the release of the NE from the vesicle?
Guanethidine and Bretylium
What prevents reuptake of NE into the neuron?
Cocaine and imipramine
What molecule methylates NE in the metabolism process?
COMT
What molecule oxidizes NE in metabolism process?
MAO
What mediated the effects of Epi, NE and Dopamine?
G protein coupled receptors
What are the fight or flight responses?
increased heart rate increased breathing or respiratory rate decreased secretion muscle tension pupil dilation digestion slows inhibit bladder contraction bronchi dilate
what are the rest and digest response?
lower heart rate lower breathing or respiratory rate pupil constrict digestion stimulation secretion salivation increase bronchi constrict sexual arousal
What are adrenergic agonist?
drugs that mimic the effects of NE and Epi
What is the function alpha 1 receptor?
vascular constriction of smooth muscle
What is the function of beta 1 receptor?
increase heart ionotrophy and chronotrophy
What is the function of beta 2 receptor?
respiratory and uterine smooth muscle and skeletal muscle relaxation and vasodilation
inotrophy
strength of the muscle contraction of the heart
what are the effects of the alpha 1 receptor stimulation?
vasconstriction of the smooth muscle will result in the increase of BP due to perophreal vasoconstriction
What mechanism is activated upon stimulation of alpha 1 receptors?
Baroreflex compensatory mechanism to slow the heart rate
Which catecholamine has the greatest affinity for alpha 1 receptor?
Epi then NE then isoproterenol
What are the antagonist of the alpha 1 adrenergic receptor?
phentolamine and phenoxybenzamine
If it is harder for the heart to pump, what will the heart response be?
reduce HR
Where are alpha 2 receptors located ?
postsynaptic CNS neurons peripheral vasculature Platelets Adrenergic and Cholinergic nerve terminals Fat Cells Some vascular smooth muscle
What is the effect of stimulation of the alpha 2 receptors ?
activation of the receptors in the periphery causes vasoconstriction
activation of the receptors in the CNS decreases the release of NE from CNS neurons
What does the activation of the beta 1 receptors result?
higher cardiac output
higher heart rate
higher inotrophy
higher dromotrophy which is higher velocity of conduction
What are the effects of the beta 2 receptors stimulation?
vasodilation of skeletal blood vessels
bronchial smooth muscle dilation
What are the antagonist of the beta receptors?
Beta Blockers
Where are the beta 3 receptors located ?
Adipose tissue
Bladder
What does stimulation of the beta 3 receptors do?
Help patients breath better
Where are dopamine receptors located?
CNS and Renal Vasculature
Pulmonary artery and heart
The stimulation of the D1 receptor produces what effect?
Vasodilation of the Renal ,Splanchnic and
Coronary vessels
Renal natriuresis
Increased kidney perfusion
Changing what aspect of dopamine will affect its effect on organ systems?
Concentration
The selectivity of a drug is dependent upon what characteristics?
Receptor regulation which is the number and function is regulated by other drugs and catecholamines , hormone changes, age and disease states.
Dominant receptor located on the tissue
Concentration of the drug
What drugs are the alpha agonist?
phenylephrine
clonidine
Which drug has higher affinity for alpha 2 receptor?
clonidine
which drug has a higher affinity for alpha 1 receptor among the alpha agonist?
phenylephrine
What are the mixed alpha and beta receptor agonist?
NE
EPI
Which catecholamine is completely non selective among all receptors?
EPI
Which beta receptor does NE prefer?
B1
What drugs are beta agonist?
Dobutamine
Isoproterenol
Which beta agonist is nonselective?
isoproterenol
which beta receptor does dobutamine prefer?
beta 1
what drugs are the dopamine agonist?
dopamine
Does dopamine have a higher affinity for alpha or beta receptors?
beta more than alpha
dopamine prefer D1 over D2 receptor
True or False
False
Nonselective D receptor agonist
What is the function of the alpha 1 receptor?
Vascular smooth muscle contraction
Increase inotrophy of heart
Contract prostate
Contract pilomotor smooth muscle for erecting hair
Dilate pupils through pupillary dilator muscle
What are the alpha 2 receptor functions?
Postsynaptic neurons=Decrease the release of NE from postsynaptic neurons
Platelets =Promote platelet aggregation
Adrenergic and Cholinergic=Inhibit transmitter release from adrenergic and cholinergic nerve terminals
Vascular smooth muscle=Contract some vascular smooth muscle
Fat Cells=Inhibit lypolysis of fat cells
What are the beta 1 receptor functions?
Increase force and rate of contraction of the heart
Increase the release of renin from juxtaglomerular cells to promote vasoconstricton
What are the functions of the beta 2 receptors?
respiratory, uterine and vascular smooth muscle relaxation
promote potassium uptake in skeletal muscle
Activates glycogenolysis and glucagon release