walls than veins, thus their greater wall thickness. This is because they have to carry pumped blood away from the heart to all the organs and tissues that need the oxygenated blood. The endothelial lining of each is similar. Excessive proliferation of vascular smooth muscle cells contributes to the progression of pathological conditions, such as vascular inflammation, plaque formation, atherosclerosis, restenosis, and pulmonary hypertension. Recent studies have shown that the majority of cells within atherosclerotic plaque, the predominant cause of heart attack and stroke, are vascular smooth muscle cell derived. See also Mural cell References External links Image of smooth muscle in the arterial walls Smooth muscle in stomach wall Angiology