Receptors

Question 1

alpha-1 adrenergic receptors

Answer 1

Gq-protein coupled receptor

in vascular and visceral smooth muscle

increase vascular smooth muscle contraction, pupillary dilatory muscle contraction (mydriasis), and intestinal and bladder sphincter muscle contraction

Question 2

alpha-2 adrenergic receptors

Answer 2

Gi-protein coupled receptor

in pancreas, presynaptic terminals, and salivary glands

decrease sympathetic (adrenergic) outflow, insulin release, lipolysis, and aqueous humor production; increase platelet aggregation

Question 3

beta-1 adrenergic receptors

Answer 3

Gs-protein coupled receptor

in heart and kidneys

increase heart rate, contractility, renin release, and lipolysis

Question 4

beta-2 adrenergic receptors

Answer 4

Gs-protein coupled receptor

in bronchioles, cardiac muscle, liver, and visceral smooth muscle

vasodilation, bronchodilation; increased lipolysis, insulin release, glycogenolysis, aqueous humor production, cellular K+ uptake; decreased uterine tone

Question 5

beta-3 adrenergic receptors

Answer 5

Gs-protein coupled receptor

in adipose tissue

increase lipolysis, thermogenesis in skeletal muscle, and bladder relaxation

Question 6

M1 cholinergic receptors

Answer 6

Gq-protein coupled receptor

mediates higher cognitive functions, stimulates enteric nervous system

Question 7

M2 cholinergic receptors

Answer 7

Gi-protein coupled receptor

decrease heart rate and contractility of atria

Question 8

M3 cholinergic receptors

Answer 8

Gq-protein coupled receptor

increase exocrine gland secretions (lacrimal, sweat, salivary, gastric acid), gut peristalsis, bladder contraction, bronchoconstriction, pupillary sphincter muscle contraction (miosis), ciliary muscle contraction (accommodation), insulin release, and endothelium-mediated vasodilation

Question 9

D1 dopamine receptors

Answer 9

Gs-protein coupled receptor

relaxes renal vascular smooth muscle, activates direct pathway of striatum

Question 10

D2 dopamine receptors

Answer 10

Gi-protein coupled receptor

modulates transmitter release, especially in brain; inhibits indirect pathway of striatum

Question 11

H1 histamine receptors

Answer 11

Gq-protein coupled receptor

increase nasal and bronchial mucus production, increase vascular permeability and vasodilation, bronchoconstriction, pruritus, pain

Question 12

H2 histamine receptors

Answer 12

Gs-protein coupled receptor

increase gastric acid secretion

Question 13

V1 vasopressin receptors

Answer 13

Gq-protein coupled receptor

increase vascular smooth muscle contraction

Question 14

V2 vasopressin receptors

Answer 14

Gs-protein coupled receptor

increase H2O permeability and reabsorption via upregulating aquaporin-2 in collecting tubules of kidney, increase release of vWF

Question 15

cholinomimetic agents: direct agonists

Answer 15

bethanechol, carbachol, methacholine, pilocarpine