Atheroma resulting in angina has following characteristic except -
Ans. is 'c' i.e., Lack of macrophage o Atherosclerotic plaque is composed of three major components. Cellular component --> Predeminantly smooth muscle cells and macrophages. Others are lymphocytes. Connective tissue matrix (ECM) --> Collegen, elastic fibers, proteoglycans. Lipids --> Both intracellular and extracellular. The major lipid is cholesterol and cholesterol esters. o From initiation to the development, atheromatous plaque progresses from the following stages. Type I (Initial) lesion o These are due to accumulation of isolated lipid filled macrophages (foam cells) and begins as fatty dots. o These are not visible. Type II lesion (fatty streaks) o These lesions are due to accumulation of multiple lipid-filled macrophages (foam cells). o These are the earliest visible lesion of atherosclerosis. o They are not significantly raised and thus do not cause any disturbance in blood flow. Type III (intermediate) lesion o These are same as type II with small extracellular lipid pool. Type IV (atheroma) lesion o Type II change with core of extracellular lipid. Type V lesion (fibroatheroma or mature atherosclerosis) o This lesion is mature atherosclerotic plaque which has following structure. A.Fibrous cap It may be thin or thick. It contains-Smooth muscle cells, macrophages, foam cells, lymphocytes, collegen, elastin and proteoglycans. B.Necrotic core It is deep to the fibrous cap. Contains disorganised mass of lipid (primarily cholesterol and cholesterol esters), cell debris, some foam cells, fibrin, and other plasma proteins.
Thin fibrous cap
Thick fibrous cap
Lack of macrophage
Lack of smooth muscle cell