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67 Cards in this Set
- Front
- Back
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Pre-ganglionic neurotransmitter on parasympathetic limb?
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ACh
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Pre-ganglionic neurotransmitter on sympathetic limb?
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ACh
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Post-ganglionic neurotransmitter on parasympathetic limb?
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ACh
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Post-ganglionic neurotransmitter on sympathetic limb?
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NE
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Only effector organ that is soley innervated by SNS?
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Adrenal medulla
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PNS is housed where?
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-Cranial-sacral, originates in brainstem.
-S2-S4 -CN III (oculomotor), CN VII (facial), CN IX (glossopharyngeal), CN X (vagus) |
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SNS is housed where?
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Thoraco-lumbar (T1-L2)
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General functions of the ANS?
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1. Neural & hormonal regulation of smooth muscle, cardiac muscle, & glands.
2. Hormonal influence over non-innervated tissue 3. Homeostasis |
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Sympathetically dominated?
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1. Blood vessels
2. Sweat glands |
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Parasympathetically dominated?
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1. Intrinsic eye muscles
2. SA node 3. GI tract 4. Urinary bladder |
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The only time you would give propanolol in OR?
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Pt. w/ pheochromocytoma b/c its LONG ACTING non-selective beta adrenergic anatgonist
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Atropine?
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Anti-muscarinic
- inhibits effects of parasympathetic NS via muscarinic receptors - increase HR |
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Sympathetic sys. short/long pre-ganglionic?
Short/long post-ganglionic? |
-short pre-ganglionic
-long post-ganglionic |
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Where is the SNS ganglia in SC?
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Lateral horn (intermediate cell column)
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Explain SNS 2 neuron sys. w/ NE release?
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-SNS short pre-ganglionic neuron comes out of lateral horn of SC & releases ACh
-synpases w/ nicotinic post ganglionic receptor -post-ganglionic neuron releases NE -NE binds to alpha & beta adrenergic receptors on cardiac muscle, smooth muscle, & glands |
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Explain SNS 2 neuron sys. w/ ACh release (post-ganglionic)
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-SNS short pre-ganglionic neuron comes out of lateral horn of SC & releases ACh
-synpases w/ nicotinic post ganglionic receptor -post-ganglionic neuron releases ACh -ACh binds to muscarinic receptors on sweat glands,& arrector pili muscle. |
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Explain SNS 2 neuron sys. w/ Adrenal medulla (post-ganglionic)
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SNS short pre-ganglionic neuron comes out of lateral horn of SC & releases ACh
-synpases w/ nicotinic post ganglionic receptor Aka Adrenal medulla -Adrenal Medulla (post-ganglionic neuron) releases NE & Epi NE & Epi then bind to alpha & beta adrenergic receptors in body -80% more Epi |
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Explain SNS 2 neuron sys. w/ dopamine release
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SNS short pre-ganglionic neuron comes out of lateral horn of SC & releases ACh
-synpases w/ nicotinic post ganglionic receptor -post-ganglionic neuron releases DA -DA binds to D1 (dopamine receptors) in renal & mesenteric, & vascular smooth muscle. |
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Begining enzyme for catecholamine synthesis?
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Tyrosine
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Rate limiting step in catecholamine synthesis?
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Tyrosine hydroxylase
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Explain catecholamine synthesis?
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Tyrosine -tyrosine hydoxylase - Ldopa - Ldopa decarboxylase - dopamine - dopamine beta hydroxylase - noradrenaline - phenylethanolamine N methyltransferase - adrenaline
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What is the diff. b/w epi & NE?
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NE does not have a functional group (methyl-CH3)
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Structure of a catecholamine?
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-Amine attached to a catechol ring
-catechol ring is a benzene ring w/ hydroxyl group at position 3 & 4. |
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Primary mech. by which catechol. have their effects terminated?
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Uptake, requires less energy.
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2 enzymes primarily responsible for metabolizing catechol.?
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1. MAO (monoamine oxidase)
2. COMT (catechol-o-omethyltransferase) |
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PNS is housed where?
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Cranial-sacral (C1-C7 & S2-S4)
CN III (oculomotor), CN VII (facial), CN IX (glossopharyngeal), CN X (vagus) |
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SNS is housed where?
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Thoraco-lumbar (T1-L2)
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General functions of the ANS?
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1. Neural & hormonal regulation of smooth muscle, cardiac muscle, & glands.
2. Hormonal influence over non-innervated tissue 3. Homeostasis |
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Sympathetically dominated?
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1. Blood vessels
2. Sweat glands |
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Parasympathetically dominated?
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1. Intrinsic eye muscles
2. SA node 3. GI tract 4. Urinary bladder |
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Degradation products of NE that suggest pheochromocytoma?
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1. Metenephrine
2. Vanillymandelic acid (VMA) |
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Most of PNS is houses along which CN?
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Vagus (CN X)
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Alpha 1 receptors?
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-located on post-synaptic effector cells (vascular smooth muscle)
-excitatoty -vasoconstriction |
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Pre-synaptic alpha 2 receptors?
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-inhibit NE release
-negative feedback -decrease HR, BP, sedation, xerostomia, decrease pain at level of SC b/c NE is excitatory NE |
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Explain negative feedback of pre-synaptic alpha 2 receptors?
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When too much NE is being released from the post-ganglionic pre-synaptic neuron, some will diffuse back & agonize the post ganglionic pre-synaptic alpha 2 receptors & inhibit further NE release.
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post-synaptic alpha 2 receptors?
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-constrict vascular smooth muscle (esp. veins)
-similar effect of alpha 1 receptors, primarily venous |
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Beta 1 receptors?
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-excitatory
-mainly in myocardium |
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Beta 2 receptors?
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-inhibitory, except in liver & myocardium
-found in bronchial smooth muscle & uterus |
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Explain the molecular mech. (pathway)of adrenergic receptors?
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-Hormones (1st messenger) agonize adrenergic receptors.
-1st messenger binds w/ G-protein mediated receptor (a1, a2, beta)either Gi or Gs -GTP to GDP & then increase cAMP -DAG, IP3 are produced & elicit response -kinase phosphorylates other substrates & produces downstream effects |
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Epinephrine dose response?
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-low dose affects B2 (vascular beds, decrease BP & lungs, bronchodilation, & uterine relaxation)
-Mod. dose affects B1(increase HR & contractility) -High dose affects alpha receptors (vasoconstriction increase BP) |
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Norepinephrine?
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-stimulates B1 but no B2
-almost purely alpha & significant B1 |
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Dopamine?
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- low dose: D1,D2,& D3 receptors dilate renal & intestinal vascular beds
- mod. dose: B1 agonist - high dose: alpha response **new data suggest dopamine worsens renal perfusion in ARF pts. |
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Enzyme that makes ACh?
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CHAT (choline-acetyl-transferase)
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Beta 1 receptors?
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-excitatory
-mainly in myocardium |
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Enzyme that breaks down ACh?
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acetylcholinesterase
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Nicotinic receptors?
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-ligand gated cation channels (no 2nd messengers)
-cholinergic receptors & respond to endogenous neurotransmitter ACh & exogenous neurotransmitter nicotine -post-ganglionic on parasympathetic & sympathetic limb & NMJ |
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Subtypes of nicotinic receptors?
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-Nicotinic neuronal (Nn)found pre-ganglionic on parasympathetic & sympathetic limb
-Nicotinic muscular (Nm) found on NMJ |
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Autonomic ganglia neurotransmitter?
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-ACh
-Nicotine |
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Physiologic response of administering nicotine or ACh?
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-unpredictable b/c both nicotine & ACh will agonize some subset of receptors on both preganglionic sympathetic & parasympathetic sys.
-can predict outcome if adminster a ganglionic blocking agent decamethonium or hexamethonium |
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Effect of nicotinic receptor activation?
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-open cation or ligand gated channel
-Ca2+ enters & EPSP or EPP occurs. |
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Muscarinic receptors?
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-found on post-ganglionic parasympathetic limb
-responds to ACh & amanita muscarina & inocybe - mushroom -cholinergic -G-protein mediated receptors |
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Subtypes of muscarinic receptors?
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-M1 (postganglionic neurons)
-M2 (myocardium) -M3 (smooth muscle & glands) -M4 & M5 |
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Atropine subclinical dose consequence?
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-atropine is anti-muscarinic
-at subclinical dose will agonize pre-synaptic M2 receptors & decrease HR |
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Molecular mech. for M1,M3, & M5 receptors?
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-activate G-protein
-stimulate PLC (phospholypase C) -increase IP3 -increase intracellular Ca2+ -smooth muscle contraction, glandular secretion |
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Molecular mech. for M2 & M4 receptors?
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-activate Gi protein
-inhibit adenyl cyclase -decrease cAMP levels -inhibit voltage gated Ca2+ channels in atria (decrease HR) -activate a G protein that opens K+ channel |
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Phenylephrine?
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-a1 agonist, increase contractility by 2-3x
-upregulation of a1 receptors in failing heart or ischemia |
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Epinephrine cardiovascular effects?
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-primarily B1
-Increased chronotropy, inotropy & dromotropy -increase MVO2 & workload -shortens sys. & dys. |
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Epinephrine vascular effects?
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-increased blood flow to skeletal muscle (B2)
-increased coronary blood flow -vasoconstriction or & vasodilation -increase BP but small doses may decrease BP |
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Epinephrine resp. effects?
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-relaxes bronchial smooth muscle
-inhibits release of inflammatory mediators (B2) |
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Epinephrine metabolic effects?
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-inhibits insulin release (a2), although some enhancement by B2.
-glucagon secretion is enhanced by B1 & B2 -glycogenolysis is stimulated (B1 & B2) |
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NE cardiac effects?
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-largely alpha agonist w/ some B1
-Increases SVR (alot) so it decreases HR to baseline via baroreceptor response |
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Isoproterenol?
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-pure non-selective B agonist
-decrease PVR due to B2 effects & increase HR to due B1. -Relaxes smooth muscle (bronchial & GIT) -low alpha affinity -great bronchiodilator |
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Turbutaline (Brethine)?
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-Selective B2 agonist
-uterine smooth muscle relaxation via B2 -Increase HR via B1 (spill over) -B agonist increase blood glucose & increase release of free fatty acids |
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Dobutamine?
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-synthetic dopamine analog but does not act at D receptors
-predominantly B1 -(+) isomer 10x more potent as B agonist -also has alpha antagonist properties -Mor prominent inotrope than chronotrope (may be cardiac a1 effect) -facilitates AV conduction (may cause ectopy) -short 1/2 life (2min) |
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When & why is dobutamine given?
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-short term cardiac decompensation states (low CO)
-after cardiac sx, acute MI, or CHF -b/c more B1 effects (more inotropy than chronotropy) |
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When is dobutamine not given?
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-severe CHF b/c down regulation of B receptors that may hamper dobutamine's effectiveness
-not best choice for hypotension - |
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Fenoldopam?
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-D1 agonist w/ no alpha or B activity.
-natriuretic peptide |
