Atherosclerotic Plaque

Atherosclerotic plaques (and other vessel wall pathology) can occlude arteries atherosclerosis often develops at branch points or curving portions along extracranial and intracranial large arteries, locations where blood flow is slowed and more turbulent. The internal carotid artery is particularly at risk. Exactly where disease tends to occur, though, and how quickly it progresses apparently reflect the individual's genetic background. Additional factors that may stimulate plaque growth include hypertension and cigarette smoking.

Atherosclerosis involves focal accumulation of lipid, smooth muscle cells, foamy macrophages, and, eventually, cholesterol crystals under the surface lining (endothelium) of the artery. With time, such an accumulation can form an elevated plaque that protrudes into the vessel's lumen and significantly reduces blood flow. Perhaps the analogy of a kitchen drain pipe becoming gradually plugged with cooking grease and sludge will help you visualize what is happening.

The atheromatous plaque is divided into three distinct components:

• The atheroma ("lump of porridge", from Athera, porridge in Greek,), which is the nodular accumulation of a soft, flaky, yellowish material at the center of large plaques, composed of macrophages nearest the lumen of the artery
• Underlying areas of cholesterol crystals
• Calcification at the outer base of older/more advanced lesions.

Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens and narrows your arteries. The flow of oxygen-rich blood to your organs and other parts of your body is reduced. This can lead to serious problems, including heart attack, stroke, or even death.