Autonomic Nervous System (Adrenergic)

Question 1

Adrenergic

Answer 1

Agents that mimic or clock effects of norepinephrine or epinephrine (sometimes dopamine)

Question 2

Location of a1 receptors?

Answer 2

Postsynaptic effector cells, smooth muscle, prostate, heart

Increases contraction

Question 3

Location of a2 receptors?

Answer 3

Presynaptic adrenergic nerve terminal (Inhibits transmitter release), platelets (Aggregation), lipocytes (Inhibits lipolysis), some vascular smooth muscle (Contraction)

Question 4

Location of B1 receptors?

Answer 4

Postsynaptic effector cells, heart, lipocytes, brain; presynaptic adrenergic and cholinergic nerve terminals, j-g renal tubules, ciliary body epithelium

Increases rate and force of contraction

Question 5

Location of B2 receptors?

Answer 5

Postsynaptic effector cells, especially smooth muscle (lung) & cardiac muscle

Promotes smooth muscle relaxation, potassium uptake, activates lipolysis

Question 6

What are the direct acting non-selective adrenergic agonists?

Answer 6

Isoproterenol -> B1 = B2

Epinephrine -> B1 = B2 >> a1 a2

Norepinephrine -> a1 >> B1

Question 7

What are the selective adrenergic agonists?

Answer 7

Phenylephrine -> a1

Dobutamine -> B1 > B2

Albuterol -> B2

Question 8

What are the indirect adrenergic agonists?

Answer 8

Amphetamine -> Releasing agent

Ephedrine -> Releasing agent (catecholamines)

Cocaine -> Reuptake inhibitor (blocks the NET)

Question 9

What are the vascular effects of a1 and B2 receptors on peripheral vascular resistance?

Answer 9

a1 -> Increase arterial resistance

B2 -> Promotes relaxation

Question 10

What are the a2 agonists?

Answer 10

Clonidine and dexmedetomidine

Selective a2, presynaptic receptor action inhibits the release of endogenous neurotransmitter (NE) which decreases sympathetic outflow and can decrease HR, BP, conduction of heart and cause sedation, analgesia in CNS

Question 11

What is a nonselective and indirect acting a1 and a2 antagonist?

Answer 11

Reserpine -> binds to and destroys neuronal storage vesicles, very long acting

Question 12

What is an a1 antagonist?

Answer 12

Doxazosin -> a1 >>>>> a2 causes decreased peripheral vasoconstriciton, to decreased TPR

Question 13

What is a nonselective B and a1 antagonist?

Answer 13

Labetalol -> B1 = B2 >= a1 >> a2 (3rd generation)

Question 14

What is a nonselective B antagonist?

Answer 14

Propranolol -> B1 = B2 (1st generation)

Question 15

What is a selective B1 antagonist?

Answer 15

Metoprolol -> B1 >>> B2 (2nd generation)