ARTHEROSCLEROSIS Flashcards
(41 cards)
What is atherosclerosis? (1)
the progressive degeneration of artery walls.
what are the steps of development? (3)
-endothelial damage
-raised blood pressure
-lesion formation and inflammatory response
what are unhealthy arteries? (2)
unhealthy arteries, the walls have strands of yellow fat deposited under the endothelium.
what are classified as death from atherosclerosis? (1)
premature deaths that occur before 75 years.
how and what causes raised blood pressure? (2)
these deposits start to impede blood flow and contribute to raised blood pressure also thickening of artery walls leads to loss of elasticity.
what are healthy arteries? (2)
healthy arteries have pale, smooth linings and the walls are elastic and flexible.
what occurs if these deposits form in coronary arteries? (1)
the progressive reduction of blood flow impairs oxygenation of the cardiac muscle fibres leading to chest pains (angina).
what and how are lesions formed? (3)
-when the smooth lining breaks down the circulatory blood is exposed to these fatty fibrous deposits.
-lesions are known as atheromatous plagues.
-further deposition occurs as cholesterol and triglycerides accumulate and smooth fibres muscle and collagen fibres proliferate in the plague.
what and how is endothelial damage caused? (3)
-fat in unhealthy arteries builds up from certain lipoproteins and from cholesterol that may be circulating in the blood.
-this damage causes white blood cells (microphages) to include the fatty streaks where they begin to take up cholesterol from low density lipoproteins and develop fibrous connective tissue forming an atheroma.
what and how an inflammatory response triggered? (2)
blood platelets tend to collect at the exposed, toughened surface and these platelets release factprs that trigger a defensive response (inflammation) which includes blood clotting.
-this is called thrombus until it breaks into the blood stream (called embolus)
what major risk factors of coronary heart disease that cannot be controlled? (3)
-increasing age
-genetic factors
-some races
what is a heart attack also called? (1)
myocardial infarction
what major risk factors of coronary heart disease can we control or reduce? (4)
-hypertension
-high levels of cholestrol in blood
-smoking
-alcohol
what can cause a blockage with an artery? (1)
a blockage can be caused by an embolus being swept into a small artery or arteriole that is narrower than the diameter of the clot causing this.
what can result from a blockage in an artery? (1)
the blood supply to the tissue downstream of the block is deprived of oxygen. without oxygen the tissue dies.
what occurs when an embolus blocks an artery in the brain? (1)
when an embolus blocks an artery in the brain, a stroke occurs.
what happens when a blockage occurs in a artery that has been weakened by atherosclerosis? (2)
the remaining layers may be stretched and bulge under the pressure of the blood pulses. Ballooning of the wall like this is called an aneurysm which could burst at any time.
what is meant by a heart attack? (1)
when a heart muscle dies by blockage causes the heart to cease being an effective pump.
how do genetic factors effect the risk of CHD? (2)
the occurrences of heart attacks at relatively early age frequently runs in families suggesting genes can confer vulnerability to CHD. children of parents of heart diseases are distinctively more likely to develop the condition.
what happens when a stroke occurs? (2)
neurones of the brain depend on a continuous supply of blood for oxygen and glucose. within a few minutes of blood supply being lost, the the neurones affected will die. Which cannot be replaced. this blockage results in loss of some body functions controlled by that region of the brain.
what is defined as high blood pressure? (1)
systolic pressure greater than 140mmHg and diastolic pressure greater than 90mmHg.
How does increasing age effect the risk of CHD? (2)
over 80% of people who die from CHD are 65 years or more though chances could be related to changes in lifestyle in early life.
what is the result of hypertension? (3)
it increases the work load on the heart, causing it to enlarge and weaken with time. It also causes damage to blood vessels accelerating the onset of atherosclerosis. Brain and kidney can also be damaged. increases the risk of stroke making a brain haemorrhage more likely
why are men much more likely to develop CHD than females? (1)
the possession of the Y chromosome predisposes a greater risk because of the production of the hormone oestrogen which inhibits the formation of atheroma and reduces the risk of CHD.
