5.1 Describe The Changes In Artery Structure Associated With Circulatory Disease
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This blog is going to look at how the artery structure is effected due to circulatory disease. Circulatory disease begins when there is a malfunction of special cells that line the arteries.The cells are called endothelial cells and they are the key to atherosclerosis and it is the under laying cause of the dysfunction of endothelial. At the beginning of artherosclerosis there is inflammation and immune cell activation at the endothelial level, this then causes the malfunction of the endothelial and damage is then eventually caused to the artery and there is a build up of plaque.
Our arteries have three layers, the outside layer is mainly connective tissue and it gives the structure to support the under layers. The middle layer is smooth muscle, this contracts and dilates which allows the control of the blood flow and to maintain blood pressure. The inner layer is a thin layer of endothelial cells and this provides a smooth, protective surface. The endothelial cells prevent toxic, blood borne substances from getting to the smooth muscle of the artery. The cells also help to respond to a change in blood pressure and they release a substance into the cells of the smooth muscle that help change the muscle tone of the artery. They also secrete chemicals, these chemicals create a protective response in the artery for when there is an injury, one of the messages is sending a signal to the smooth muscle cells and white blood cells to gather around a site where injury may be.
As we get older the endothelium gets leaky, this lets lipids and toxins out and they break through the endothelial layer and enter the smooth muscle cells. The smooth muscle cells then build up where the artery is damaged and the artery then looses some of it's flexibility. The white blood cells are then signalled by the endothelium and they gather along the cell wall, the white blood cells then produce pro - inflammatory substances such as leukotrienes and prostaglandins, they also damage free radicals that attack the endothelium. Has this is happening toxins start to break through into the arterial wall and lipids like ldl, cholesterol and triglycerides gather and become oxidized.
Once the oxidized process has begun the body then starts to try and build up a immune response, this causes the white blood cells to attack the fats which then causes more inflammation in the arterial wall. The smooth muscle cells then try and build up a collagen this is to form a cap over the damaged area, however the mixture of the white blood cells, smooth muscle cells and the lipids that are oxidized create a plaque deposit. The plaque deposit then over time forms a build up of calcium that accumulates on it which then creates a brittle cap. The brittle cap could then rupture which could result in the formation of a blood clot, which could then lead to a heart attack or stroke, or could even effect the lungs. However there is also the possibility that the blood clot stays where it is and doesn't cause a problem.
There is also artheroselerosis, which is a build up of fatty tissue, this causes the artery wall which is normally smooth with no friction to be rough and also to build up with plaque. This is caused by high blood pressure and as the the plaque builds up the lumen decreases causing the blood pressure to raise even more.
The reason blood clots occur or people have heart attacks or strokes is because there is a lack of blood flow and oxygen to the heart because the arteries are blocked due to circulatory disease, which is causing the build up of plaque.
Overall we can do things to try and prevent ourselves getting circulatory disease and that is to try and lead a sensible healthy lifestyle. Smoking and a high cholesterol diet are a big factor in the disease along with high blood pressure, all of which can be controlled if we want to make changes for the good of ourselves.
This blog is going to look at how the artery structure is effected due to circulatory disease. Circulatory disease begins when there is a malfunction of special cells that line the arteries.The cells are called endothelial cells and they are the key to atherosclerosis and it is the under laying cause of the dysfunction of endothelial. At the beginning of artherosclerosis there is inflammation and immune cell activation at the endothelial level, this then causes the malfunction of the endothelial and damage is then eventually caused to the artery and there is a build up of plaque.
Our arteries have three layers, the outside layer is mainly connective tissue and it gives the structure to support the under layers. The middle layer is smooth muscle, this contracts and dilates which allows the control of the blood flow and to maintain blood pressure. The inner layer is a thin layer of endothelial cells and this provides a smooth, protective surface. The endothelial cells prevent toxic, blood borne substances from getting to the smooth muscle of the artery. The cells also help to respond to a change in blood pressure and they release a substance into the cells of the smooth muscle that help change the muscle tone of the artery. They also secrete chemicals, these chemicals create a protective response in the artery for when there is an injury, one of the messages is sending a signal to the smooth muscle cells and white blood cells to gather around a site where injury may be.
As we get older the endothelium gets leaky, this lets lipids and toxins out and they break through the endothelial layer and enter the smooth muscle cells. The smooth muscle cells then build up where the artery is damaged and the artery then looses some of it's flexibility. The white blood cells are then signalled by the endothelium and they gather along the cell wall, the white blood cells then produce pro - inflammatory substances such as leukotrienes and prostaglandins, they also damage free radicals that attack the endothelium. Has this is happening toxins start to break through into the arterial wall and lipids like ldl, cholesterol and triglycerides gather and become oxidized.
Once the oxidized process has begun the body then starts to try and build up a immune response, this causes the white blood cells to attack the fats which then causes more inflammation in the arterial wall. The smooth muscle cells then try and build up a collagen this is to form a cap over the damaged area, however the mixture of the white blood cells, smooth muscle cells and the lipids that are oxidized create a plaque deposit. The plaque deposit then over time forms a build up of calcium that accumulates on it which then creates a brittle cap. The brittle cap could then rupture which could result in the formation of a blood clot, which could then lead to a heart attack or stroke, or could even effect the lungs. However there is also the possibility that the blood clot stays where it is and doesn't cause a problem.
There is also artheroselerosis, which is a build up of fatty tissue, this causes the artery wall which is normally smooth with no friction to be rough and also to build up with plaque. This is caused by high blood pressure and as the the plaque builds up the lumen decreases causing the blood pressure to raise even more.
The reason blood clots occur or people have heart attacks or strokes is because there is a lack of blood flow and oxygen to the heart because the arteries are blocked due to circulatory disease, which is causing the build up of plaque.
Overall we can do things to try and prevent ourselves getting circulatory disease and that is to try and lead a sensible healthy lifestyle. Smoking and a high cholesterol diet are a big factor in the disease along with high blood pressure, all of which can be controlled if we want to make changes for the good of ourselves.
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