ANS Flashcards
ALPHA 1 -
Signal Transduction
Effector
Second Messenger
Gq
Increase Phospholipase C
Increase IP3, DAG, Ca+2
ALPHA 2 -
Signal Transduction
Effector
Second Messenger
Gi
Decrease Adenylate cyclase
Decrease cAMP
BETA 1 -
Signal Transduction
Effector
Second Messenger
Gs
Increase Adenylate cyclase
Increase cAMP
BETA 2 -
Signal Transduction
Effector
Second Messenger
Gs
Increase Adenylate cyclase
Incrase cAMP
MUSCARINIC 1/3/5 -
Signal Transduction
Effector
Second Messenger
Gq
Increase Phospholipase C
Increase IP3, DAG, Ca+2
MUSCARINIC 2/4-
Signal Transduction
Effector
Second Messenger
Gi
Decrease Adenylate cyclase
Decrease cAMP
NICOTINIC (ANS ganglia, NMJ, & CNS)
Signal Transduction
Effector
Second Messenger
Ion channels
N/A
N/A
DOPAMINE 1 (post-synaptic)
Signal Transduction
Effector
Second Messenger
Gs
Increase Adenylate cyclase
Increase cAMP
DOPAMINE 2 (pre-synaptic)
Signal Transduction
Effector
Second Messenger
Gi
Decrease Adenylate cyclase
Decrease cAMP
VASOPRESSIN 1 (vasculature) -
Signal Transduction
Effector
Second Messenger
Gq
Increase Phospholipase C
Increase IP3, DAG, Ca+2
VASOPRESSIN 2 (renal tubules) -
Signal Transduction
Effector
Second Messenger
Gs
Increase Adenylate cyclase
Increase cAMP
HISTAMINE 1 -
Signal Transduction
Effector
Second Messenger
Gq
Increase Phospholipase C
Increase IP3, DAG, Ca+2
HISTAMINE 2-
Signal Transduction
Effector
Second Messenger
Gs
Increase Adenylate cyclase
Increase cAMP
MYOCARDIUM
SNS Receptor
Action
B1
Increased contractility
MYOCARDIUM
PNS Receptor
Action
M2
Decreased contractility
CONDUCTION SYSTEN
SNS Receptor
Action
B1
Increased HR, Increased conduction speed
CONDUCTION SYSTEN
PNS Receptor
Action
M2
Decreased HR, Decreased conduction speed
ARTERIES
SNS Receptor
Action
A1 > A2
Vasoconstriction
*No PNS receptors
VEINS
SNS Receptor
Action
A2 > A1
Vasoconstriction
*No PNS receptors
MYOCARDIUM VASCULATURE
SNS Receptor
Action
B2
Vasodilation
*No PNS receptors
SKELETAL MUSCLE VASCULATURE
SNS Receptor
Action
B2
Vasodilation
*No PNS receptors
RENAL VASCULATURE
SNS Receptor
Action
DA
Vasodilation
*No PNS receptors
MESENTERIC VASCULATURE
SNS Receptor
Action
DA
Vasodilation
*No PNS receptors
BRONCHIAL TREE
SNS Receptor
Action
B2
Bronchodilation
BRONCHIAL TREE
PNS Receptor
Action
M3
Bronchoconstriction
RENAL TUBULES
SNS Receptor
Action
A2
Diuresis
*No PNS receptors
RENIN RELEASE
SNS Receptor
Action
B1
Increased renin release
*No PNS receptors
SPHINCTER MUSCLE (IRIS)
SNS Receptor
Action
No SNS receptor
SPHINCTER MUSCLE (IRIS)
PNS Receptor
Action
M3, M2
Contraction (miosis)
RADIAL MUSCLE (IRIS)
SNS Receptor
Action
A1
Contraction (mydriasis)
*No PNS receptor
CILIARY MUSCLE
SNS Receptor
Action
B2
Relaxation (far vision)
CILIARY MUSCLE
PNS Receptor
Action
M3, M2
Contraction (near vision)
SPHINCTERS
SNS Receptor
Action
A1
Contraction
SPHINCTERS
PNS Receptor
Action
M
Relaxation
GI MOTILITY & TONE
SNS Receptor
Action
A1/A2/B1/B2
Decrease
GI MOTILITY & TONE
PNS Receptor
Action
M
Increase
SALIVARY GLANDS
SNS Receptor
Action
A2
Decrease
SALIVARY GLANDS
PNS Receptor
Action
M
Increase
GALLBLADDER & DUCTS
SNS Receptor
Action
B2
Relaxation
GALLBLADDER & DUCTS
PNS Receptor
Action
M
Contraction
BETA CELLS - Alpha and Beta
SNS Receptor
Action
A2 - Decrease insulin release
B2 - Increase insulin release
*No PNS receptor
LIVER
SNS Receptor
Action
A1/B2
Increase serum glucose
UTERUS - Alpha and Beta
SNS Receptor
Action
A1 - Contraction
B2 - Relaxation
*No PNS receptor
BLADDER TRIGONE & SPHINCTER
SNS Receptor
Action
A1
Contraction
BLADDER DETRUSOR
SNS Receptor
Action
B2
Relaxation
BLADDER TRIGONE & SPHINCTER
PNS Receptor
Action
M
Relaxation
BLADDER DETRUSOR
PNS Receptor
Action
M
Contraction
SWEAT GLANDS
SNS Receptor
Action
A1
Increase secretion
SWEAT GLANDS
PNS Receptor
Action
M
Increase secretion
ANS innervation of eye
A1 stimulation
radial muscle contraction
mydriasis = pupil DILATION
ANS innervation of eye
Muscarinic stimulation
sphincter muscle contraction
miosis = pupil CONSTRICTION
BRR
If the heart rate increases in setting of hypotension OR decrease in setting of hypertension, BRR is said to be
preserved
Volatile gas
Decrease or Increase effectiveness of BRR
Decrease in dose-dependent
Volatile gas
which gas impairs BRR lease
Iso
mild B1 agonist properties
IV Induction agents and BRR
Thiopental
Preserves
IV Induction agents and BRR
Propofol
Depresses - decrease in HR with decrease in SVR
IV Induction agents and BRR
Ketamine
activates SNS - increase HR but no change in SVR
In critically ill pts, with exhausted catecholamine reserve, myocardial depressant effects may be noticed
IV Induction agents and BRR
Etomidate
No change in HR, small decrease in SVR. Hypovolemic pts my experience hypotension
Vasodilators and BRR
Hydralazine
Preserves BRR
Decrease in SVR with Increase in HR
Vasodilators and BRR
Nitroprusside
Preserves BRR
Vasodilators and BRR
Nitroglycerine
Preserves BRR
Beta blockers and BRR
May prevent a compensatory rise in HR in setting of hypotension
BB and BRR
Labetalol
BB
Also antagonizes A-1 receptor
May increase the risk of orthostatic hypotension
Catecholamines and BRR
NE
Effect on HR is dose-dependent
Lower doses - B1 chronotropic effects prevail
Higher doses - A1 vasoconstrictive effects overshadow B1 = BRR fall in HR
Catecholamines and BRR
epi, dobutamine, isoproterenol, dopamine
BRR NOT preserved
HR increases
Phenylephrine and BRR
BRR is preserved
Bradycardia is side effect
Not a catecholamine
Adrenergic Agonists
NE
Low dose - B1 selective (increase HR, increase inotropy) High dose ( - stimulates A1, A2, B1 - increase SVR to increase BP and decrease HR via BRR
0.02-0.4 mcg/kg
Adrenergic Agonists
NE
When is ideal to use?
Ideal drug for low SVR states like sepsis or post-CPB hypotension due to low afterload
Adrenergic Agonists
NE
When to avoid use?
In the setting of cardiogenic shock bc it increase afterload and MVO2
Treatment of NE extravasation
Injection with phentolamine (2.5-10 mg in 10 mL of dilute)
Stellate ganglion block
Adrenergic Agonists
Epi
Low dose (0.01-0.03 mcg/kg) - b1 and B2 (increase HR, increase CO, increase inotropy, decrease SVR) Intermediate dose(0.03-0.15 mcg/kg) - Mixed alpha and beta High dose (>0.15)- Alpha effects predominate and SVT common
Adrenergic Agonists
Epi
Key points
Bronchodilation - think bronchospasm!
Mast cell stabilization - think anaphylaxis!
Prolongs duration of LA
Increases serum glucose
Causes hypokalemia due to transcellular K+ shift
Adrenergic Agonists
Dopamine
Low dose (1-2 mcg/kg) - Renal vasodilation and incrase RBF Intermediate (2-10 mcg/kg) - Increase HR, increase inotropy, increase CO High dose (10-20 mcg/kg) - Vasopressor effect - Alpha effects overshadow
Adrenergic Agonists
Isoproterenol
Synthetic catecholamine derived from dopamine
Stimulates B1, B2
0.02-0.5 mcg/kg
increase HR, incrase inotropy, incrase CO
Vasodilation decrease SVR
Can cause dysrthymias and tachycardia
Adrenergic Agonists
Isoproterenol
What to be aware/cautious of?
reduction in SVR can be so severe as to drop DBP, and this can impair CPP
Also makes it a poor choice for septic shock
Adrenergic Agonists
Isoproterenol
Key points
chemical PM for bradycardia unresponsive to atropine or for the pt w a denervated heart
Treatment of bronchoconstriction
Treatment of cor pulmonale
Adrenergic Agonists
Dobutamine
Sympathomimetic amine
Potent B1 and mild B2 agonist
Increase HR, Increase inotropy, increase CO
0.5-15 mcg/kg
Adrenergic agent
Phenylephrine
Alpha1 receptor
Direct acting
Increases SVR
Increases CPP
Reflex bradycardia
Good for conditions where increase afterload is required, such as hypertrophic cardiomyopathy or tetralogy of Fallot
Infusion 10-200 mcg/min
Adrenergic agent
Ephedrine
Non-catecholamine
Direct and Indirect
A1, A2, B1, B2
Increase HR, Increase inotropy, increase CO, increase SVR
Multiple doses can cause tachyphylaxis - progressively smaller response to a given dose after multiple administrations
Adrenergic agent
Ephedrine
When doesn’t ephedrine work?
When neuronal catecholamine stores are:
- depleted - SEPSIS
- absent - denervated heart (HEART TRANSPLANT)
Adrenergic agent
Ephedrine
Pts on MAOI are at risk for what?
Hypertensive crisis
Adrenergic agent
Vasopressin
Where does it come from?
Produced by the hypothalamus and released by the Posterior Pituitary Gland
Adrenergic agent
Vasopressin
How does it restore BP?
- V1 receptor simulation causes intense vasoconstriction
- V2 receptor simulation stimulates the synthesis and insertion of aquaporins into the walls of the collecting ducts. This increase water (but not solute) reabsorption and lowers serum osmolarity
Adrenergic agent
Vasopressin
Key points
IV bolus - 0.5-1 unit
IV infusion - 0.01-0.04 units/min
First line therapy for ACEI or ARB induced vasoplegia that’s refractory to catecholamines
*NOTE: methylene blue is next best drug
Adrenergic agent
Vasopressin
Overdose can cause what?
Hyponatremia and seizures
What causes K+ to shift into cells?
Alkalosis - Activating Na+/K+ pump
B2 agonists (albuterol, ritodrine, epi)
Theophylline
Insulin
What causes K+ to shift out of cells?
Acidosis - Activating H+/K+ pump
Cell lysis
Hyperosmolarity
Succ