Arteriosclerosis

There is an apparent coronary artery network, in the human heart. On a zoomed view of one of the coronary arteries, three layers are seen. These are; Tunica externa on the outer, Tunica muscularis in the middle, and Tunica interna layer at the inner. When cholesterol, found as LDL molecule in the blood, is carried at high levels for a long time, these cholesterol molecules precipitate on the artery’s surface. Then, it leaks through the gaps of the epithelial cells. They form a deposit in between the Tunica interna and the Tunica muscularis layers. This fatty deposit is called plaque. As the plaque grows bigger, spreading in the artery, it bulges in the lumen forming a lump and this reduces blood flow. This is called Arteriosclerosis, also known as hardening of the arteries. With time epithelial cells may split at a point. This situation activates platelets and enables the formation of fibrin thread. Clot forms as a result. This clot is known as thrombus and prevents the blood flow in the arteries.