What is the primary function of nitroglycerin?

The primary function of nitroglycerin is to dilate blood vessels. This is important in the treatment of conditions such as angina pectoris, where the heart muscle does not receive enough oxygen-rich blood. By relaxing the smooth muscle in the walls of blood vessels, nitroglycerin allows for increased blood flow, which reduces the workload on the heart and alleviates symptoms of chest pain. This vasodilatory effect helps to lower blood pressure and decrease the heart's demand for oxygen, making it a vital medication in managing cardiac conditions. Other options like increasing heart rate, reducing blood sugar levels, or acting as a pain reliever are not functions of nitroglycerin.