Introduction
Atherosclerosis is a build-up of plaques (fatty deposits) on the inside of the arteries. A plaque can build up until it restricts the flow of blood through the artery which increases blood pressure and there is a chance of the plaque completely blocking the artery to a point when no blood can pass through. Plaque tends to build up in the arteries surrounding the heart (coronary arteries) and neck (carotid arteries). The problem with restricted blood flow is that organs become damaged and stop working properly which could be fatal. Also if a plaque ruptures it will lead to the formation of a blood clot which could potentially block off the blood supply to the heart or brain resulting in a heart attack or stroke. In this way atherosclerosis is linked to peripheral arterial disease where the blood supply to the legs is blocked and coronary heart disease where the coronary arteries become clogged with plaques. How does atherosclerosis develop? It begins with damage to the endothelial lining of blood vessels which may be caused by high blood pressure or the chemicals in tobacco smoke. Atherosclerosis occurs in arteries rather than veins because the endothelial lining is more likely to get damaged when the blood is flowing under high pressure. Once the damage to the lining has occurred, the body responds and signals for white blood cells to arrive at the site. These cells accumulate chemicals in the blood such as cholesterol which is one of the main constituents of plaque. As a result of accumulation of these chemicals an atherome will form on the arterial lining. Calcium salts and fibrous tissue also build up and surround the plaque which hardens it, therefore this area of the artery will lose some flexibility. This build-up of plaque will narrow the lumen of the artery which increases blood pressure. Higher blood pressure will cause further damage elsewhere leading to more build-up of plaques. As a result blood pressure will get even higher which will cause more problems. Effect on health? Atherosclerosis leads to a raised blood pressure - a higher pressure will damage smaller delicate blood vessels. For example: blood vessels leading to the kidneys the eye and the brain will become damaged as these vessels are not strong enough to take the force of an increased pressure of blood. Aneurysms – as the plaque continues to accumulate, blood can build up behind the clump which puts the artery wall under more pressure than usual which causes it to weaken. This may lead to the artery splitting open causing internal bleeding. Heart disease - angina is a common example of heart disease involving blockage of the coronary arteries. As plaques build-up in the arteries surrounding the heart, blood flow becomes more and more restricted. As a result the heart is pumping on a restricted supply of oxygen meaning it may have to respire anaerobically at times. This process brings about a pain in the chest which may spread into the arms and often causes breathlessness. Another common example of heart disease would be the heart attack also known as myocardial infarction. This is more severe than angina as it involves complete blockage of a coronary artery resulting in a section of the heart lacking an oxygen supply. A heart attack occurs as a result of a part of the heart being starved of oxygen. Strokes – this involves the blood supply to the brain being temporarily cut off. It can be caused by blockage in the artery due to plaque build-up or blood clots. What increases the risk of developing atherosclerosis? The risks of developing atherosclerosis can be increased by several factors some of which cannot be modified as you were born with it and some which can be modified by a change in lifestyle.
1 Comment
Mr Lovat
3/1/2016 01:49:36 am
Wow! Loads of information. You need to be able to understand the stages that lead to atherosclerosis, its affect on health and the factors that increase the risk of its development. This blog clearly demonstrates your ability to do this. Well done!
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Ciara Branagan
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October 2016
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