JBL EMT Practice Exam 2025 - Free EMT Practice Questions and Study Guide

Epinephrine, also known as adrenaline, is a natural hormone secreted by the adrenal glands. It has a variety of functions in the body, such as increasing heart rate and blood pressure and constricting blood vessels. Option A, dilating lung passages, is not an action of epinephrine. Instead, it is a function of another natural hormone called beta-agonist, which is used to treat asthma and other respiratory conditions. Option B, decreasing blood pressure, is also incorrect as epinephrine actually increases blood pressure. Option C, constricting blood vessels, is the opposite of what option B suggests and is in fact a function of epinephrine. Option D correctly states that epinephrine is secreted by the adrenal glands, however this does not make it the correct answer as the question is asking for the action of epinephrine, not its source.