heart disease
- Created by: Narey7Emily97
- Created on: 06-01-14 16:07
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- Heart disease
- Heart disease kills more people in the UK than any other disease. Almost half of heart disease deaths are from coronary arteries.
- Atheroma
- Atheroma is a fatty deposit that forms within the wall of an artery. It begins as fatty streaks that are accumulations of white blood cells that have taken up low density lipoproteins.
- These streaks enlarge to form an irregular patch or atheromatous plaque which commonly occurs in larger arteries and are made up of deposits of cholesterol fibers and dead muscle cells.
- They bulge into the lumen of the artery causing it to narrow so that the blood flow through it is reduced.
- These streaks enlarge to form an irregular patch or atheromatous plaque which commonly occurs in larger arteries and are made up of deposits of cholesterol fibers and dead muscle cells.
- Atheromas increase the risk of two potentially very dangerous conditions: thrombosis and aneurysm
- Thrombosis
- If an atheroma breaks through the endothelium of the blood vessel it forms a rough surface that interrupts the otherwise smooth flow of blood.
- This may result in the formation of a blood clot, or thrombus, in a condition known as thrombosis.
- This thrombus may block the blood vessel reducing or preventing the supply of blood to tissues beyond it.
- The region of tissue deprived of blood often dies as a result of the lack of oxygen glucose and other nutrients that the blood normally provides.
- Sometimes the thrombus is carried from its place of origin and lodges in and blocks another artery.
- The region of tissue deprived of blood often dies as a result of the lack of oxygen glucose and other nutrients that the blood normally provides.
- This thrombus may block the blood vessel reducing or preventing the supply of blood to tissues beyond it.
- This may result in the formation of a blood clot, or thrombus, in a condition known as thrombosis.
- If an atheroma breaks through the endothelium of the blood vessel it forms a rough surface that interrupts the otherwise smooth flow of blood.
- AQA BIOLOGY
- Aneursym
- Atheromas the lead to the formation of a thrombus also weaken the artery walls.
- These weakened points swell to form a balloon like blood filled structure called an anuerysm
- aneursyms frequently burst, leading to haemorrhage and therefore loss of blood to the region of the body served by that artery
- A brain aneurysm is known as a cerebrovascular accident (CVA) or stroke
- aneursyms frequently burst, leading to haemorrhage and therefore loss of blood to the region of the body served by that artery
- These weakened points swell to form a balloon like blood filled structure called an anuerysm
- Atheromas the lead to the formation of a thrombus also weaken the artery walls.
- Thrombosis
- Atheroma is a fatty deposit that forms within the wall of an artery. It begins as fatty streaks that are accumulations of white blood cells that have taken up low density lipoproteins.
- Atheroma
- Myocardial infarction (heart attack)
- This term refers to a reduced supply of oxygen to the muscle of the heart
- It results from a blockage in the coronary arteries.
- If this occurs close to the junction of the coronary artery and the aorta, the heart will stop beating because its blood supply will be completely cut off
- If the blockage is further along the coronary artery the symptoms will be milder because a smaller area of muscle will suffer oxygen deprivation
- If this occurs close to the junction of the coronary artery and the aorta, the heart will stop beating because its blood supply will be completely cut off
- It results from a blockage in the coronary arteries.
- This term refers to a reduced supply of oxygen to the muscle of the heart
- risk factors associated with coronary heart disease
- Smoking
- There are two main constituents of tobacco smoke that increase the likelihood of heart disease
- nicotine
- it stimulates the production of the hormone adrenaline which increases heart rate and raises blood pressure
- as a consequence there is a greater risk of suffering coronary heart disease
- nicotine also makes the red blood cells more sticky this leads to a higher risk of thrombosis and hence of strokes or heart attacks
- it stimulates the production of the hormone adrenaline which increases heart rate and raises blood pressure
- carbon monoxide
- combines with haemoglobin in the red blood cells to form carboxyhaemoglobin.
- It thereby reduces the oxygen carrying capacity of the blood.
- to supply the equivalent quantity of oxygen to the tissues, the heart must work harder
- this can lead to raised blood pressure that increases the risk of coronary heart disease and strokes.
- the reduction in the oxygen carrying capacity of the blood means that it may be insufficient to supply the heart muscle during exercise
- this leads to chest pain or myocardial infarction
- the reduction in the oxygen carrying capacity of the blood means that it may be insufficient to supply the heart muscle during exercise
- this can lead to raised blood pressure that increases the risk of coronary heart disease and strokes.
- to supply the equivalent quantity of oxygen to the tissues, the heart must work harder
- It thereby reduces the oxygen carrying capacity of the blood.
- combines with haemoglobin in the red blood cells to form carboxyhaemoglobin.
- nicotine
- There are two main constituents of tobacco smoke that increase the likelihood of heart disease
- High blood pressure
- lifestyle factors e.g. excessive stress, certain diets and lack of exercise increase high blood pressure which increases the risk of heart disease
- as there is already a higher pressure in the arteries, the heart must work harder to pump blood into them and is therefore more prone to failure
- higher blood pressure within the arteries means that they are more likely to develop an aneurysm and burst causing haemorrhage
- to resist the higher pressure within them the walls of the arteries tend to become thickened and may harden restricting the flow of blood
- lifestyle factors e.g. excessive stress, certain diets and lack of exercise increase high blood pressure which increases the risk of heart disease
- Blood cholesterol
- cholersterol is an essential component of membranes - it is a biochemical which must be transported in the blood. it is carried in the plasma as tiny spheres of lipoproteins. There are two types
- high density lipoproteins which remove cholesterol from tissues and transport it to the liver for excretion. They help protect arteries against heart disease
- low density lipoproteins which transport cholesterol from the liver to the tissues including the artery walls which they infiltrate leading to the development of atheroma and hence heart disease
- cholersterol is an essential component of membranes - it is a biochemical which must be transported in the blood. it is carried in the plasma as tiny spheres of lipoproteins. There are two types
- Diet
- there are a number of things that increase the risk of heart disease
- high levels of salt raise blood pressure
- high levels of saturated fat increase low density lipoprotein levels and hence blood cholesterol concentration
- foods that act as antioxidants e.g. vitamin C reduce the risk of heart disease
- there are a number of things that increase the risk of heart disease
- Smoking
- Heart disease kills more people in the UK than any other disease. Almost half of heart disease deaths are from coronary arteries.
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