The endothelium is the thin membrane that lines the blood vessels, it is also the largest organ in the endocrine system, the chemical messenger system. The endothelium contains millions of microscopic “medicine bottles” that supply the body with a variety of medicines. One of them is nitric oxide. Nitric oxide helps dilate the arteries which increase blood flow and nutrients to the organs. The figure above shows a healthy blood vessel. Eating the right foods and exercising allows the ”medicine bottles” to open and keep the blood flowing freely. The figure below shows a vessel where the person sits too much and eats too much of the wrong things. The bottles are not able to open because too much “sticky stuff” accumulates. Movement is the best way to increase nitric oxide.