CRNA Interview Practice Exam 2025 – Complete Study Resource

Epinephrine is a sympathomimetic agent that interacts with various adrenergic receptors in the body, leading to a range of physiological effects. When considering the receptor subtypes, epinephrine has moderate effects primarily on the Beta-2 receptors.

Beta-2 receptors are found in various tissues, including the smooth muscles of the bronchial tree and blood vessels, and their activation leads to relaxation of these muscles, which is particularly important in bronchodilation and vasodilation. This receptor subtype's responsiveness to epinephrine contributes to the medication's effectiveness in managing conditions such as asthma and anaphylaxis, where widening of the airways and improvement of blood flow are necessary.

Comparatively, while epinephrine does have significant effects on alpha-1 and beta-1 receptors, its action on beta-2 receptors is noted for being moderate, especially when contrasted with the predominant actions on alpha-1 (vasoconstriction) and beta-1 (increased heart rate and contractility) receptors. Muscarinic receptors, associated with the parasympathetic nervous system, are not influenced by epinephrine, as they are separate from adrenergic pathways.

Understanding these interactions helps to highlight the nuanced pharmacological effects of ep