USMLE STEP 1 Pharmacology Questions and 100% Verified

What are the major functions of the α1 receptor? -ANSWER Increase vascular smooth muscle contraction, increase pupillary dilator muscle contraction (mydriasis), increase intestinal and bladder sphincter muscle contraction What are the major functions of the α2 receptor? -ANSWER Decrease sympathetic outflow, decrease insulin release, decrease lipolysis, increase platelet aggregation, decrease aqueous humor production What are the major functions of the β1 receptor? -ANSWER Increase heart rate, increase contractility, increase renin release, increase lipolysis What are the major functions of the β2 receptor? -ANSWER Vasodilation, bronchodilation, increase lipolysis, increase insulin release, decrease uterine tone (tocolysis), ciliary muscle relaxation, increase aqueous humor production What are the major functions of the M1 receptor? -ANSWER CNS, enteric nervous system What are the major functions of the M2 receptor? -ANSWER Decrease heart rate and contractility of atria What are the major functions of the M3 receptor? -ANSWER Increase exocrine gland secretions (e.g., lacrimal, salivary, gastric acid), increase gut peristalsis, increase bladder contraction, increase bronchoconstriction, pupillary sphincter muscle contraction (miosis), ciliary muscle contraction (accommodation) What are the major functions of the D1 receptor? -ANSWER Relaxes