Fatty streak
Encyclopedia
Fatty streak, though composed of macrophage white blood cells, not fat, is the term generally given to the earliest stages of atheroma
, as viewed at autopsy, looking at the inner surface of arteries
, without magnification.
The fatty streak is the first grossly visible lesion in the development of atherosclerosis
. It appears as an irregular off white to yellow-white discoloration near the luminal surface of the artery. The streaks are not actually fat but small collections of monocyte
-derived macrophage
s located beneath the inner, endothelial
layer of arteries
. The fatty streak mainly consists of foamy appearing macrophage cells, sometimes with some additional T lymphocytes, aggregated platelet
s, localized smooth muscle cells, etc.
Fatty streaks may be precursor of atheromas and not all fatty streaks are destined to become fibrous plaques.
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-white color and were named because they were thought to "look like" "streaks of fat" against the otherwise quite red/pink muscular tissue background forming the wall of arteries
.
Almost all children above the age of 10 years show evidence of fatty streaks, with coronary fatty streaks beginning to form in the adolescent years.
Atheroma
In pathology, an atheroma is an accumulation and swelling in artery walls that is made up of macrophage cells, or debris, that contain lipids , calcium and a variable amount of fibrous connective tissue...
, as viewed at autopsy, looking at the inner surface of arteries
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
, without magnification.
The fatty streak is the first grossly visible lesion in the development of atherosclerosis
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
. It appears as an irregular off white to yellow-white discoloration near the luminal surface of the artery. The streaks are not actually fat but small collections of monocyte
Monocyte
Monocytes are a type of white blood cell and are part of the innate immune system of vertebrates including all mammals , birds, reptiles, and fish. Monocytes play multiple roles in immune function...
-derived macrophage
Macrophage
Macrophages are cells produced by the differentiation of monocytes in tissues. Human macrophages are about in diameter. Monocytes and macrophages are phagocytes. Macrophages function in both non-specific defense as well as help initiate specific defense mechanisms of vertebrate animals...
s located beneath the inner, endothelial
Endothelium
The endothelium is the thin layer of cells that lines the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. These cells are called endothelial cells. Endothelial cells line the entire circulatory system, from the heart...
layer of arteries
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
. The fatty streak mainly consists of foamy appearing macrophage cells, sometimes with some additional T lymphocytes, aggregated platelet
Platelet
Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days...
s, localized smooth muscle cells, etc.
Fatty streaks may be precursor of atheromas and not all fatty streaks are destined to become fibrous plaques.
The macrophage
Macrophage
Macrophages are cells produced by the differentiation of monocytes in tissues. Human macrophages are about in diameter. Monocytes and macrophages are phagocytes. Macrophages function in both non-specific defense as well as help initiate specific defense mechanisms of vertebrate animals...
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
Cholesterol
Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...
and other fats.
En-mass the foamy macrophages usually have an off white to yellow-white color and were named because they were thought to "look like" "streaks of fat" against the otherwise quite red/pink muscular tissue background forming the wall of arteries
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
.
Almost all children above the age of 10 years show evidence of fatty streaks, with coronary fatty streaks beginning to form in the adolescent years.
See also
- AtheromaAtheromaIn pathology, an atheroma is an accumulation and swelling in artery walls that is made up of macrophage cells, or debris, that contain lipids , calcium and a variable amount of fibrous connective tissue...
- AtherosclerosisAtherosclerosisAtherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
- ArteryArteryArteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
- HeartHeartThe heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
- Coronary circulationCoronary circulationCoronary circulation is the circulation of blood in the blood vessels of the heart muscle . The vessels that deliver oxygen-rich blood to the myocardium are known as coronary arteries...
- Coronary catheterizationCoronary catheterizationA coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional purposes....
- AngiogramAngiogramAngiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins and the heart chambers...
- LipoproteinLipoproteinA lipoprotein is a biochemical assembly that contains both proteins and lipids water-bound to the proteins. Many enzymes, transporters, structural proteins, antigens, adhesins, and toxins are lipoproteins...
s