Repeated USMLE Questions- Pharmacology- 269

Q- Epinephrine acts to dilate bronchial smooth muscle through which one of the following receptors?

A- Alpha-1-adrenoreceptors

B- Alpha-2-adrenoreceptors

C- Beta-1-adrenoreceptors

D- Beta-2-adrenoreceptors

D- Beta-2-adrenoreceptors- Epinephrine causes bronchodilation primarily through stimulation of β₂-adrenergic receptors on bronchial smooth muscle.

Q- Which of the following locations is the site of action of furosemide to inhibit sodium reabsorption?

A- Ascending limb of loop of Henle

B- Collecting tubules

C- Descending limb of loop of Henle

D- Distal convoluted tubules

A- Ascending limb of loop of Henle- Furosemide blocks the Na⁺/K⁺/2Cl⁻ cotransporter in the thick ascending limb of the loop of Henle, powerfully inhibiting sodium reabsorption and producing strong diuresis.

Q- Which one of the following drugs blocks dopamine uptake transporter?

A- Alcohol

B- Cocaine

C- Marijuana

D- Nicotine

B- Cocaine- Cocaine blocks the dopamine reuptake transporter, increasing dopamine levels in the synaptic cleft and producing its stimulant and addictive effects