Distribution of Adrenergic Receptor Subtypes

Question 1

Alpha 1 (a1)

Answer 1

• most vascular smooth m = contracts to increase vascular resistance
• pupillary dilator m = contracts for mydriasis (dilation of eyes)
• pilomotor smooth m (hair) = contracts to erect hair

Question 2

Alpha 2 (a2)

Answer 2

• adrenergic and cholinergic nerve terminals= inhibits nt release
• platelets = stimulates aggregation
• some vascular smooth m = contracts

Question 3

Beta 1 (B1)

Answer 3

• heart = stimulates rate and force

- justaglomerular cells = stimulates renin release

Question 4

Beta 2 (B2)

Answer 4

• respiratory, uterine, and vascular smooth m = relaxes
• liver = stimulates glycogenolysis
• somatic motor nerve terminals (voluntary muscle) = causes tremor

Question 5

Beta 3 (B3)

Answer 5

-fat cells = stimulates lipolysis

Question 6

Dopamine 1 (D1)

Answer 6

-renal and other splanchnic blood vessels = relaxes (reduces resistance)

Question 7

Dopamine 2 (D2)

Answer 7

-nerve terminals = inhibits adenylyl cyclase