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Atherosclerosis: Difference between revisions
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→Three layers of arterial vessel
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The intima is located closest to the arterial lumen and is therefore most ‘intimate’ with the blood. This layer is composed of a single layer of endothelial cells (endothelium), connective tissue, and several smooth muscle cells. The endothelium functions as an active metabolic barrier as well as a carrier between blood and the arterial wall. It plays a crucial role in atherosclerosis. Connective tissue consists of a matrix of collagen, proteoglycans and elastin. Lymphocytes, macrophages and other types of inflammatory cells may occasionally reside in the intima. <br /> | The intima is located closest to the arterial lumen and is therefore most ‘intimate’ with the blood. This layer is composed of a single layer of endothelial cells (endothelium), connective tissue, and several smooth muscle cells. The endothelium functions as an active metabolic barrier as well as a carrier between blood and the arterial wall. It plays a crucial role in atherosclerosis. Connective tissue consists of a matrix of collagen, proteoglycans and elastin. Lymphocytes, macrophages and other types of inflammatory cells may occasionally reside in the intima. <br /> | ||
The media is the middle layer and | The media is the middle layer and its inner and outer boundaries are formed by the internal and external elastic laminae. The media consists of layers of smooth muscle cells with contractile and synthetic function. As for the contractile function, smooth muscle cells enable vasoconstriction and vasodilatation. As for the synthetic function, they are responsible for the growth of the vascular extracellular matrix.<br /> | ||
The most external vessel wall layer is called the adventitia and contains fibroblasts, connective tissue, nerves, lymphatics and vasa vasorum. Inflammatory cells may occasionally reside in the adventitia. <br /> | The most external vessel wall layer is called the adventitia and contains fibroblasts, connective tissue, nerves, lymphatics and vasa vasorum. Inflammatory cells may also occasionally reside in the adventitia. <br /> | ||
There is a constant dynamic interchange between the arterial wall and its cellular components and the surrounding extracellular matrix. By | There is a constant dynamic interchange between the arterial wall and its cellular components and the surrounding extracellular matrix. By understanding the physiology of this dynamic interchange and the function of each cellular component, the dysfunction of these cellular components leading to atherogenesis can be better understood. <br /> | ||
=== Cellular components involved in atherosclerosis === | === Cellular components involved in atherosclerosis === | ||