03/18/2013
Biol 2401-C04
Md Ismail Hossain
Indroduction
Atherosclerosis:
After cancer, heart disease is the second cause of death in the world. One of the prominent causes of heart disease is atherosclerosis. In general, atherosclerosis means the narrowing of blood vessel which ultimately hinders the blood flow through the vessel. Various substances accumulate on the inner wall of blood vessel and with time the blood vessel start to lose its elasticity and become harder. In some cases, the sclerotic vain and artery can be blocked permanently and results in severe consequences. “It causes nearly 75% of cardiovascular related deaths and is found in 80 - 90% of Americans over the age of 30”. The severity of atherosclerosis varies depending on which arteries are blocked. If an artery that is responsible for carrying large volume of blood is blocked; for instance, blockage of the artery of heart can cause death.
Development of atherosclerosis: The appearance of atherosclerosis does not occur abruptly. It starts with a process called plaque formation. The plaque is a relatively hard substance consists of mainly fat, cholesterol, and calcium. First, the fatty substances start to deposit on the inner wall of the blood vessel. Then cholesterol also accumulates on those fatty substances. Finally the deposition of calcium on the plaque makes it inflexible. With time the depositing mass becomes larger and makes the passage of blood vessel narrow. The organ or tissue connected to that artery then may suffer from depravity of blood and oxygen. If the organ is heart, then a person can experience angina pectoris; a characteristic pain sensation. Sometimes the artery can be blocked fully and cause heart attack in case of heart artery blockage and stroke in case of blockage of brain artery which can cause death. In some cases the plaque can be broken down, and shredded fragments can be carried out through blood to
Cited: “Atherosclerosis”, Web, 18 March 18, 2013. www.umm.edu “Hardening of the Arteries: Atherosclerosis, Plaque buildup-arteries”. A.D.A.M Medical encyclopedia, Web, 18 March 2013. www.ncbi.nlm.nih.gov