Fatty streak
From Biocrawler, the free encyclopedia.
Fatty streak is the term generally given to the earliest stages of atheroma, as viewed at autopsy, looking at the inner surface of arteries, without magnification. It is not visible by current technologies in living humans, even by IVUS, the most advanced imaging technology for seeing artery walls.
The fatty streak is first grossly detectable lesion in the development of atherosclerosis. It appears as an irregular yellow discoloration near the luminal surface of the artery. Actually the streaks are not fat, but collections of macrophage white blood cells, located under the endothelial inner lining of arteries. The fatty streak mainly consists of foamy appearing macrophage cells, sometimes with some additional T T lymphocytes, aggregated platelets, localized smooth muscle cells, etc.
The macrophage cells, under a microscope, have a foamy-like appearance because of large collections of membrane bound vesicles within their cytoplasm. Since cholesterol within cells resides primarily within the cell membranes, the large accumulation of membranes results in an elevated local content of membrane bound cholesterol and other fats. En-mass the foamy macrophages usually have an off white to yellow color and were thought to look like streaks of fat against the otherwise quite red/pink muscular tissue background forming the wall of arteries.
