National Center for Competency Testing (NCCT) Medical Assistant Practice Test

Nitroglycerin primarily acts on the heart and vascular system. It is a medication that dilates blood vessels, leading to decreased workload on the heart and improved blood flow. When administered, nitroglycerin causes relaxation of smooth muscle in the vascular endothelium, which results in vasodilation. This effect helps to relieve angina (chest pain) by reducing the amount of oxygen the heart requires and increasing the oxygen supply to the myocardium (heart muscle). The impact of nitroglycerin is particularly vital in treating conditions related to the heart, such as ischemic heart disease, where improved blood flow can alleviate symptoms and prevent damage during episodes of reduced oxygen supply. Other parts of the body, such as the lungs, kidneys, and muscles, do not primarily respond to nitroglycerin in the same therapeutic context as the heart does. Thus, the primary action of nitroglycerin on the heart is crucial for its role in cardiovascular therapy.