Adrenergic Drugs and Beta-blockers Quiz

Pharmacological action of adrenergic drugs and beta-blockers on the human body

• The sympathetic division of the nervous system triggers the Fight or Flight response, while the parasympathetic division triggers the Rest and Digest response.
• Adrenergic drugs affect receptors stimulated by norepinephrine or epinephrine, which are found in the sympathetic division of the nervous system.
• The sympathetic division adjusts to stressful situations such as trauma, fear, hypoglycemia, cold, and exercise.
• Two families of receptors, α and β, have been identified in the sympathetic division.
• The α1 receptors cause vasoconstriction, mydriasis, and increased closure of the internal sphincter of the bladder.
• The α2 receptors inhibit the release of NE, acetylcholine, and insulin.
• The β1 receptors increase lipolysis, myocardial contractility, and the release of renin.
• The β2 receptors cause vasodilation, bronchodilation, relaxed uterine smooth muscle, increased glycogenolysis, and the release of glucagon.
• The β3 receptors cause lipolysis.
• Adrenergic antagonists bind to adrenoceptors but do not trigger the usual receptor-mediated intracellular effects.
• Beta-blockers lower blood pressure in hypertension without inducing postural hypotension, and they can treat angina, cardiac arrhythmias, myocardial infarction, congestive heart failure, hyperthyroidism, and glaucoma.
• Beta-blockers can be classified into first, second, and third generations, and they reduce heart rate, decrease myocardial contractility, and decrease the effects of exercise on heart rate and cardiac output.