Autonomic Nervous System Flashcards
Adrenergic stimulation of the eye effects what two structures, via what receptor
Pupil (dilated) via A1
Cliary muscle (relaxation-far vision) via B2
Cholinergic stimulation of the eye effects what two structures, via what receptor
Pupil Miosis (constriction) via M3,M2
Ciliary body (contraction-near vision) via M3,M2
Adrenergic stimulation of the heart effects what structures of the heart, what effect via what receptor
SA node (increased HR) via B1
AV node and conduction system (increased conduction velocity) via B1
Ventricles (increased force of contraction) via B1
Cholinergic stimulation of the heart effects what structures of the heart, what effect via what receptor
SA node (decreased HR) via M2
AV node and conduction syst. (decreased conduction velocity-AV block) via M2
Ventricles (decreased force of contraction) via M2
Adrenergic stimulation of blood vessels effect what specific structures, what effect via what receptor
Most arteries & veins (constriction) via *A1/a2
Arteries of skeletal muscle (constriction) via A1
Arteries of skeletal muscle (relaxation) via B2
*A1 vasoconstriction counters SM arteries vasodilation in fight or flight situation
- Cholinergic stimulation of blood vessels effect what specific structures, what effect via what receptor
Sympathetic cholinergic fibers cause arteries and veins (dilation) NO receptor
Arteries of skeletal muscle (dilation) via M3 SYMPATHETIC CHOLINERGIC fibers
Adrenergic stimulation of lungs effect what specific structures, what effect via what receptor
Muscles of the Trachea and Bronchials, (relaxation) via B2 Bronchial glands (secretion) B2
Cholinergic stimulation of lungs effect what specific structures, what effect via what receptor
Muscles of the Trachea and Bronchials (constriction) M2=M3 Bronchial glands (stimulation) M3
Adrenergic stimulation of stomach/intestines effect what specific function, what effect via what receptor
Motility and tone (decreased) via A1/A2
Smooth muscle sphinters (contraction) via A1
Secretion (inhibited) A2
Cholinergic stimulation of stomach/intestines effect what specific function, what effect via what receptor
Motility and tone (increased) via M2=M3
Smooth muscle sphinters (relaxation) via M3
Secretion (stimulated) via M3
Adrenergic stimulation of kidney effect what specific function, what effect via what receptor
Renin secretion (increased) via B1
Cholinergic stimulation of kidney effect what specific function, what effect via what receptor
trick quesiton, there is no cholinergic stimulation of kidney
Adrenergic stimulation of adrenal gland effect what specific function, what effect via what receptor
trick question, there is no adrenergic stimulation of adrenal gland
- Cholinergic stimulation of adrenal gland effect what specific function, what effect via what receptor
release of Epi/NE via SYPATHETIC CHOLINERGIC fibers
Adrenergic stimulation of bladder effect what specific structures, what effect via what receptor
Detrusor muscle (bladder relaxation) via B2 Trigone & sphincter (contraction) via A1
Cholinergic stimulation of bladder effect what specific structures, what effect via what receptor
Detrusor muscle (bladder contraction) via M3 Trigone & sphincter (relaxation) via M3
Adrenergic stimulation of gravid uterus effect what specific function, what effect via what receptor
relaxation via B2
contraction via A1
Cholinergic stimulation of gravid uterus effect what specific function, what effect via what receptor
trick question, there is no cholinergic effect on uterus
Adrenergic stimulation of Penis & seminal vesicles effect what specific function, what effect via what receptor
Ejaculation via A1
- Remember adrenergic “shoot”
Cholinergic stimulation of Penis & seminal vesicles effect what specific function, what effect via what receptor
Erection via M3
- Remember cholinergic “point”
Adrenergic stimulation of sweat glands effect what specific function, what effect via what receptor
Palm of hand (minimal secretion) via A1
Cholinergic stimulation of sweat glands effect what specific function, what effect via what receptor
Generalized secretion via SYMPATHETIC CHOLINERGIC fibers M1
Adrenergic stimulation of liver effect what specific function, what effect via what receptor
Glycogenolysis & Gluconeogenesis via A1/B2
Cholinergic stimulation of liver effect what specific function, what effect via what receptor
trick quesiton, there is no cholinergic stimulation of liver
Adrenergic stimulation of beta cells of pancreas effect what specific function, what effect via what receptor
Insulin increase via B2
Insulin inhibition via A2
Cholinergic stimulation of beta cells of pancreas effect what specific function, what effect via what receptor
trick question, there is no cholinergic stimulation of beta pancreas cells
Adrenergic stimulation of fat cells effect what specific function, what effect via what receptor
lipolysis via B1,B3
Cholinergic stimulation of fat cells effect what specific function, what effect via what receptor
No innervation
The PSNS has neuronal fibers in what where
cranium and sacrum
What are the 4 cranial nerves assoc. with PSNS
cranial nerves III, VII, IX, and X
What are the sacral levels assoc. with PSNS
S2 thru S4
The sympathetic’s (thoracolumbar) nervous system is spans what levels of the vertebral column
T1-L2
What are the major differences between the somatic and autonomic systems
somatic system needs external neural stimulation to effect a response
ANS, organs and glands are regulated within ANS and can function without external control
somatic system, all reflexes are mediated in CNS
ANS, visceral reflexes can occur in periphery (autonomic dysreflexia)
Is the somatic nervous system a one or two neuron systems?
One
Is PSNS and SNS a one or two neuron system
parasymp-always two
Sympath- mostly two, but one with adrenal medulla (relases ACh directly on gland, gland then releases Epi to target organs)
the postganglionic SNS release what neurotransmitter mainly, and what exceptions
postganglionic SNS contains mostly adrenergic nerve fibers that release NORepi; however, it also contains cholinergic nerve fibers that secrete ACh (sweet glands, smooth muscle of skeletal muscle arteries, and adrenal gland)
- the SNS uses only a single neuron to communicate with adrenal cortex
What are the characteristics of the autonomic innervation of effector organs
No recognizable end-plate (like in skeletal muscle)
nerve fibers run along membrane of effector cells
branches are beaded by varicosities (enlargements)
- not covered with Schwann cells
- contain synaptic vesicles
- approx. 20,000 per neuron
What are the three types of autonomic sensory receptors found throughout the body
Mechanoreptors
Chemoreceptors
Visceral Nociceptors
Mechanoreceptors respond to what three types of physical stimuli
Tension- baroreceptors
Stretch- volume receptors
Pressure- pressoreceptors/ baroreceptors
Carotid Sinus and Aortic Arch contain
Mechanoreceptors-Baroreceptors
Chemoreceptors respond to what
changes in the chemical environment such as, osmolality, pH, O2, and CO2 changes
AKA Osmoreceptors
- located throughout body atria, pulmonary vascu, kidney, GI tract
Carotid Body and Aortic Body contains
Chemoreceptors-osmoreceptors
*located throughout the body GI tract, brain, etc
Visceral Nociceptors respond to what
Pain in visceral organs which may initiate both autonomic and somatic reflexes
Referred pain is
pain felt at another location as a result of noxious stimuli to visceral organs
What are the two types of cholinergic receptors
Nicotinic
Muscarinic
What are the two types of Nicotinic receptors, where are they located, and when activated, what response is triggered
Nm (N2) receptors-Neuromuscular junction. Causes end-plate depolorization which leads to skeletal muscle contraction
Nn(N1) receptors-Autonomic Ganglia when stimulated, leads to depolorizing & firing of postganglionic neurons
What are the five types of muscuranic receptors
M1, M2, M3, M4, M5
what three Muscuranic receptors are well known
M1, M2, M3
Describe the biosynthesis pathway of epinephrine
Tyrosine transported into noradrenergic varicosity by carrier-linked sodium uptake
Then, tyrosine is hydroxylated into DOPA via tyrosine hydroxlase
Then, DOPA is decarboxylated into Dopamine via DOPA decarboxylase
Then, Dopamine is transported into a vesicle by a carrier (blocked by reserpine)
Then, Dopamine converted to Norepi by dopamine beta-hydroxylase
Then, Norepi is converted to Epi by Phenylethanolamine N-methyltransferase
List the epi precursors and their respective enzymes
Tyrosine>LDOPA>Dopamine>Norepi>Epi
Tyrosine hydroxylase>L-aa decarboxylase>Dopamine-hydroxylase> Phenylethanolamine N-methyl-transferase
What are the four fates of Norepi
- interacts with pre/post-synaptic adrenoreceptors
- diffuses out of cleft into circulation
- uptaken back into varicosity via H ions, and degraded by Monoamine Oxidase (MAO)
- Degraded post-synaptically by hepatic “CATECHOL-O-METHYL TRANSFERASE. Extrajunctionally
* Epi and Norepi share same degradation pathway. MAO>COMT
* Dopamine degradation will start with MAO or COMT
What is the degradation product of Epi/NorEpi
Methoxy-hydroxy-Mandelic Acid (VMA)
*measured in urine for patients suspected of pheochromocytomas. Will be high
What is the degradation product of Dopamine
Homovanillic Acid
What are the different types of adrenergic receptors
a1, a2, b1, b2, b3,
Dopamine:
da1-vasodilation of smooth muscle of renal & mesentery
da2- presynpathic adrenergic receptors- inhibits release of NE
Binding to beta receptors activates what adrenergic G-protein family
Gs
Binding to alpha2 receptors activate what adrenergic G-protein family
Gi
Binding to alpha1 receptors activate what adrenergic G-protein family
Gq
Cholinergic agonist are classified as
Direct acting or Indirect acting (anticholinesterases)
Cholinesterase resistant or NOT
Direct cholinergic agonists include
Bethanochol, Carbachol, Muscurine, and Pilocarpine
*cholinesterase resistant
Indirect cholinergic agonists include
Reversible- Neostigmine, pyridostigmine, edrophonium, physostigmine (crosses BBB)
Irreversible-Echothiphate (antagonizes succs), insectisides (Malathione, Parathion), nerve gases (Sarine, Tabun, Soman, DFP)
Bethanochol is used for
GI/GU tract
Stimulates gastric motility
Increased detrusor muscle initiating micturition
*Postop/Postpartum nonobstructive urinary retention, and neurogenic bladder with retention.
Dont use Bethanochol concurrently with
beta blockers
Carbachol is used for
decrease intraocular pressure
Nicotinic and Muscarinic activity
Pilocarpine is used for
to decrease IOP via stimulating ciliary muscles and produces miosis via contracton of muscles surrounding iris
Pilocarpine can worsen
retinal detachment
Echothiophate, irreversible anticholinesterase, is indicated for
open-angle glaucoma, closed-angle, cross eyed
echothiophate prolongs the effects of
succinylcholine and may cause CV collapse
What two agents are given as an antidote for insecticide, or chemical poisioning
Atropine 1st, quickly followed by 2-PAM (cholinesterase reactivator)
Alzheimer and Dementia anticholinesterases exert its effect by
increasing ACh concentration in CNS
*ACh is an excitatory NT
Cholinergic Antagonists are subdivided into antimuscarinics and antinicotinics, name each
antimuscarinics: Atropine, Scopalomine, Glycopyrrolate, Ipratropium, cogentin, artane
Antinicotinics: NMBA, depolorizing succinylcholine and decamethonium
What racemic mixture of atropine is active
Levo-rotary
Atropine is used
antisialogogue to restore cardiac rate/arterial pressure Lessen severity of AV block Asystole ingestion of muscarinic mushrooms
Atropine is contraindicated in
glucoma
pyloric stenosis
prostate hypertrophy
what is the antidote for atropine overdose
physostigmine
what is the antidote of physostigmine overdose
atropine
Scopalomine is used to treat
motion sickness
- greater effect on iris, ciliary body and secretory glands
- Don’t give in patients with Glaucoma
Glycopyrrolate is used to treat
non-emergent decrease in HR
secretions (better than atropine)
*Does not cross BBB
Ipratropium bromide (antimuscarinic) used to
treat bronchospasms
Not a first line therapy for bronchospasms
- 1st give albuterol (B2 agonist), then ipratropium (M3 antagonist), then theophyline (phosphodiesterase inhibitor), then cromyln (mast cell stabilizer), ect…..
Contraindications for Ipratropium/Propantheline Bromide
Glaucoma GI obstruction Obstructive uropathy Intestinal atony ulcerative colitis myasthenia gravis
NMBA and Depolorizing muscle blockers are antinicotinics and include
Panc, Vecu, Pipe, Roc, Atra, Doxa, Miva, Cisatr.
Succinylcholine, Decamethonium
Adrenergic AGONISTS include
Nonselective B1 and B2 Isoproterenol B1-Dobutamine B2- Terbutaline, Albuterol, Salmeterol, Ritodrine Mixed alpha and beta- Norepi, Epi, D1-Fenoldopam D2-Bromocritine A1- Phenylephrine A2-Clonidine, Dexmedetomidine Mixed a1 and a2- Cocaine, Ephedrine, Amphetamines, MAO Inhibitors
*Clonidine is a centrally acting vasoconstrictor but peripherally acting vasodilator
Adrenergic Antagonists include
Non-selective B-blockers-propranolol, sotalol, nadolol, timolol
B1 antagonists- Metoprolol, Esmolol,atenolol, bebivolol, betaxolol
Beta/Alpha 1 antagonists- *Labetalol, Carvedilol
Nonselective alpha antagonists- Phenooxybenzamine, phentolamine
A1 antagonists- prazosin, terazosin, doxazosin, tamsulosin
A2 antagonists- Yohimbine
Direct-acting sympathomimetics include
Nor, Epi, Dopamine, Isoproterenol, Dobutamine
Non-catecholamines-Phenylephrine
Indirect-acting Sympathomimetics that cause release of Norepi include
Ephedrine & Tyramine
Amphetamine
Indirect-acting Sympathomimetics that inhibit reuptake on Norepi include
Cocaine
Indirect-acting sympathomimetics that inhibit the metabolism of Norepi include
MAO inhibitors, Parnate, Marplan, etc.
- stop two weeks before anesthetic
- Tyramine-containing foods (beer, cheese)»HTN crisis
Phenylephrine primarly agonizes
alpha 1 receptors
*sign. MAP and PVR increase with decrease in HR, CO, and renal blood flow
Epineprine primarily agonizes
B1, but equally agonizes a1,a2, b2 receptors
- Increased HR, CO, and MAP
- Decreased Renal blood flow
- Bronchodilation
Ephedrine and Norepinephrine are similar and primarily agonizes
a1, a2, b1, b2
- increased HR, MAP, CO, PVR
- Norepi»>PVR
- bronchodilaton (not Norepi)
- decreased renal blood flow
Dopamine primarily agonize
a1,a2, b1 equally
- increased HR, MAP, CO, PVR, and Renal blood flow
- No effect of bronchioles
Isoproterenol primarily agonizes
B1, B2 receptors
- significant increases in HR, CO, Bronchodilation
- decreases in MAP and PVR
Dobutamine primarily agonizes
B1 and B2
- significat increase in CO
- increase in HR and MAP, renal blood flow
- decreases PVR
Phenoxybenzamine is a Alpha antagonists used to manage
pheochromocytoma a1>a2 Decreased BP with reflex tachycardia No direct effect on heart miosis
Prazosin, Doxazosin, Tamsulosin are both alpha1 agonists that
decrease BP without reflex tachycardia
*tamsulosin used to tx BPH
Labetalol is a mixed alpha/beta(nonselective) antagonist used to
decrease BP, HR, & SVR
- No effect on CO
- Labetalol IV 1:7 blocade, 1 alpha, 7 beta
- Labetalol PO 1: 4 blocade, 1 alpha, 4 beta, so alpha effects greater due to less b-effect
Beta antagonists are classified
as selective vs. non-selective
Name the b1 selective antagonists
Atenolol Acebutolol Betaxolol Bisoprolol Celiprolol Esmolol Nebivolol
- All other b-blockers are nonselective
What are the effects of beta blockers
decrease hr and contractility with smaller doses, but increased contractility with higher doses
hypotension, bronchoconstriction, inhibition of epi-induced glycogenolyisi & lipolysis
- avoid rapid withdrawl
- NPO status uneffected by patient’s on alpha/beta blockers