| Question | Answer |
| SNS | thoraco-lumbar
pre-ganglonic: short axon into prevertebral chain
post-ganlionic: long axon to organs
widely spread system
one neuron can go to MULTIPLE places |
| Exception to SNS ganglia | adrenal glands
long pre and short post
neuron that goes here ONLY goes here |
| PSNS | brain stem and sacral cord
long pre and short post
very restrictive; one neuron to one place |
| Acetylcholine (Ach) | used by PRE-ganglionic axons
agonist for NICOTINIC receptor |
| Norepinephrine (NE) | major transmitter for SNS
activates alpha 1/2 > beta 1 (mixed adrenergic agonist)
used for hypotension |
| Exception to NE for SNS | adrenal gland; chromaffin cell is post ganglia and releases Ach whcih which stimulates Epinephrine |
| Flow of transmitter signaling SNS | Ach --> nicotinic --> NE --> Alpha/beta |
| PSNS and somatic | cholinergic system |
| Flow of transmitter signaling for heart (PSNS) | Ach --> nicotinic --> Ach --> muscarinic |
| Flow of transmitter signaling for somatic | Ach --> nicotinic --> Ach --> nicotinic |
| In the SNS terminal, what is dopamine converted to? | NE |
| What causes the "lipid bubble" containing NE to move to the surface and open into the synapse? | Ca++ |
| Uptake 1 | NE transporter; pulls NE out of the synapse and back into terminal where MAO breaks it down |
| receptors that exist in tissues but DO NOT have direct innervation | Extra junctional |
| this receptor is activated to slow the system down because of too much NE; type of feedback inhibition | pre-synaptic alpha 2 |
| Enzymes that degrade trasnmitters | COMT |
| Predominant tone belongs to which system? | PSNS; exception is blood vessels |
| Low concentrations of NE will have high affinity for what? | Alpha |
| Epinephrine | beta 1/2 >> alpha 1/2 (mixed adrenergic agonist)
used for: asthma, anaphylactic shock, cardiogenic shock, and prolongs actions of local anesthetics |
| Low concentrations of Epi have high affinity for what? | beta 1/2
BUT, if dose increases 10x then alpha (dilate) will out-power beta (constrict) |
| Dopamine | alpha 1 and beta 1 (mixed adrenergic agonist)
CNS functions
was once used to treat CHF
indirectly acting adrenergic agonist |
| pseudoephedrine | alpha and beta (mixed adrenergic agonist)
used for colds |
| Phenylephrine | selective alpha 1 agonist
used for hypotension, bradycardia, and as decongestant |
| Methoxamine | selective alpha 1 agonists |
| Clondine | selective alpha 2 agonist
centrally acting anti hypertensive |
| A patient with high SNS activity will have? | HYPERtension |
| Isoproternol | beta 1/2
non selective beta agonist
cardiac transplants |
| Dobutamine | Selective beta 1 agonist
low doses will increase force of contraction but NOT heart rate |
| metaproterenol | selective beta 2 agonist
treats asthma |
| albuterol | selective beta 2 agonist
asthma: 1/2 life 6-7 hrs |
| salmetrol | selective beta 2 agonist
asthma: 1/2 life 12 hrs |
| Phentolamine | non-selective alpha 1/2 antagonist
used for OD of alpha agonists; used in pts with pheochromocytoma
Side effects: orthostatic hypotension, tachycardia, PSNS effects |
| Prazosin and silodosin | selective alpha 1 anatagonists |
| terazosin | selective alpha 1 antagonist
anti hypertensive agent
water soluble |
| Propanolol, Nadolol, Timolol and Pinolol | Non-selective beta antagonists
Tx: HTN, angina, MI, arrhythmia, stage fright, glaucoma, tremor, migraine, and anxiety
contraindication: asthma attack in those with asthma |
| Labetalol and carvedilol | non selective beta antagonists
also work on alpha 1 |
| Tyramine | dietary substance
indirectly acting adrenergic agonost |
| ephedrine | indirectly acting adrenergic agonist
can also bind to beta receptors
increase SNS activity |
| amphetamine | indirectly acting adrenergic agonist |
| Indirectly acting agonists | DO NOT bind to receptors but produce effects that look like SNS agonists
cause increase in NE release; more rapid |
| Uptake blockers | cocaine
tricyclic antidepressants
amphetamine (high doses) |
| MAO inhibitors | pargyline and tranylcypromine |
| What could cause increase in BP in those taking MAO inhibitors? | Tyramine |
| Cholinergic receptors are? | nicotinic and muscarinic |
| what has no clinical use? | Ach as muscarinic agonist |
| Bethanechol | choline esther; M agonist
effects mostly on GI and urinary systems when administered orally or subQ
prevents urinary retention
side effects: over-stimulation of M receptors |
| carbachol | choline esther; M and N agonist
produce miosis(constrict) druing ocular surgery |
| Pilocarpine | alkaloid; M agonist
NO N effects
used topically to treat glaucoma
somewhat selective for salivary glands
used for Sjorgen's syndrome
Side effects: over-stimulation of M receptors |
| Atropine and Scopolamine | Belladonna alkaloids; M anatagonists (selective)
used when PSNS tone is desirable
pre-op use for reduction of salivation/bronchial secretions
treat poisoning by AchE inhibitor |
| Atropine toxic actions | dry as a bone, hot as a pistol, red as a beet, blind as a bat, and mad as a hatter |
| Cholinesterase (AchE inhibiotrs) | agents used to enhance transmission at cholinergic junctions |
| carbamates | bind to the esteratic site of AchE (reversible) |
| Physostigmine | carbamate
readily penetrates CNS
drug of choice to treat poisoning with atropinic agents |
| Neostigmine | carbamate
does NOT penetrate CNS
used to treat myasthenia gravis
used as antidote for overdose of "curare-like" drugs |
| edrophonium | carbamate
short acting
diagnostic agent used to test for myasthenia gravis |
| Donepezil (aricept) | carbamate
short term fix for alzheimer's |
| Organophosphates | irreversibly phosphorylate serine hydroxyl at active site of AchE
ex: insecticides and nerve gases |
| what is the only way to restore function after exposure to organophosphates? | make new enzymes; could take 2-3 weeks
antidote for insecticide= 2-pralidoxine (2-PAM) |
| Botulinum toxin (Botox) | prevents Ach release from cholinergic neurons
AP occurs, but nothing happens and muscle is paralyzed |
| What is used in surgery to promote skeletal muscle relaxation? | Neuromuscular (NMJ) blocking agents |
| Tubocurarine | NMJ blocker
long duration |
| Pancuronium | NMJ blocker
intermediate duration |
| Succinylcholine | NMJ blocker
used for setting bones |
| How are NMJ blockers reversed? | With AchE |
| terbutaline | beta 2 agonist
used for premature labor to relax uterus |
