Final answer:
The question explores the mechanism of beta-blockers, medicines that block beta-adrenergic receptors and modulate the effects of adrenaline on the heart, typically to treat cardiovascular conditions.
Step-by-step explanation:
The subject of this question refers to the pharmacological classification of beta-blockers, which are medications that interact with the adrenergic system by selectively or non-selectively blocking the beta (B)-adrenergic receptors to which epinephrine and norepinephrine bind. Beta-blockers are often used in the treatment of cardiovascular diseases due to their ability to inhibit the effects of adrenaline, and are particularly beneficial for conditions such as high blood pressure, congestive heart failure, and following a heart attack.
Beta-blockers work by blocking the effects of adrenaline on the heart. For instance, metoprolol is a selective B1-blocker, acting primarily on the B1-receptors in the heart, reducing heart rate and cardiac output, while propanolol is a nonselective blocker, inhibiting both B1 and B2 adrenergic receptors, affecting heart rate, blood vessel dilation, and also the respiratory system.