Three groups of drugs are used to reduce the stickiness of platelets, the tiny blood elements that form the nucleus of a blood clot. By inhibiting the ability of platelets to clump together, the anti-platelet drugs inhibit blood clotting. These drugs are most effective in preventing abnormal blood clots from forming in arteries and are much less effective at preventing thrombosis in the veins. Aspirin and dipyridamole (Aggrenox). These drugs have a modest effect on platelet stickiness but cause fewer bleeding-related adverse effects than the other anti-platelet drugs.
The middle layer of an artery and vein contains mostly. connective tissue. simple squamous epithelium. smooth muscle. nervous tissue. 2. Arteries carry blood. away from the heart. toward the heart. both away and toward the heart.he middle layer of an artery and vein contains mostly. connective tissue. simple squamous epithelium. smooth muscle. nervous tissue. 2. Arteries carry blood. away from the heart. toward the heart. both away and toward the heart.
Arteries and veins are composed of three tissue layers. The thick outermost layer of a vessel (tunica adventitia or tunica externa ) is made of connective tissue. The middle layer ( tunica media ) is thicker and contains more contractile tissue in arteries than in veins. It consists of circularly arranged elastic fibers, connective tissue, and smooth muscle cells. The inner layer ( tunica intima ) is the thinnest layer, comprised of a single layer of endothelium supported by a subendothelial layer.