Final answer:
Alpha-adrenergic antagonists, also known as alpha-blockers, work by blocking alpha-adrenergic receptors. This prevents the neurotransmitters epinephrine and norepinephrine from binding to these receptors and produces various effects depending on their location in the body.
Step-by-step explanation:
Alpha-adrenergic antagonists, also known as alpha-blockers, work by binding to and blocking alpha-adrenergic receptors. These receptors are a type of receptor to which the neurotransmitters epinephrine and norepinephrine bind. There are two subtypes of alpha-adrenergic receptors: alpha-1 and alpha-2.
By blocking alpha-adrenergic receptors, alpha-adrenergic antagonists prevent the neurotransmitters from binding to these receptors. This leads to various effects depending on the location of the receptors in the body. For example, alpha-1 adrenergic receptors are found in the smooth muscles of blood vessels, and blocking these receptors results in vasodilation and decreased blood pressure. Alpha-2 adrenergic receptors are located presynaptically and blocking them increases the release of norepinephrine, which can have effects such as increased heart rate and blood pressure.