The internal elastic lamina or internal elastic lamella is a layer of elastic tissue that forms the outermost part of the
tunica intima
The tunica intima (New Latin "inner coat"), or intima for short, is the innermost tunica (layer) of an artery or vein. It is made up of one layer of endothelial cells and is supported by an internal elastic lamina. The endothelial cells are i ...
of blood vessels. It separates tunica intima from
tunica media
The tunica media (New Latin "middle coat"), or media for short, is the middle tunica (layer) of an artery or vein. It lies between the tunica intima on the inside and the tunica externa on the outside.
Artery
Tunica media is made up of smooth ...
.
Histology
It is readily visualized with light microscopy in sections of
muscular arteries, where it is thick and prominent, and
arterioles
An arteriole is a small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries.
Arterioles have muscular walls (usually only one to two layers of smooth muscle cells) and are the primar ...
, where it is slightly less prominent and often incomplete.
It is very thin in veins and venules.
In
elastic arteries such as the aorta, which have very regular elastic laminae between layers of
smooth muscle cells in their
tunica media
The tunica media (New Latin "middle coat"), or media for short, is the middle tunica (layer) of an artery or vein. It lies between the tunica intima on the inside and the tunica externa on the outside.
Artery
Tunica media is made up of smooth ...
, the internal elastic lamina is approximately the same thickness as the other elastic laminae that are normally present.
[http://www.ouhsc.edu/histology/text%20sections/cardiovascular.html]
There is small amount of subendothelial connective tissue between
basement membrane of endothelial cells and internal elastic lamina.
Reduplication of internal elastic lamina can be seen in elderly individuals due to
intimal fibroplasia
The tunica intima (New Latin "inner coat"), or intima for short, is the innermost tunica (layer) of an artery or vein. It is made up of one layer of endothelial cells and is supported by an internal elastic lamina. The endothelial cells are in ...
, which is part of the
aging process.
Associated pathologic conditions
*Damage in Giant cell arteritis leads to microaneurysms. Demonstration of fragmentation in this layer by elastin-
van Gieson
Van Gieson's stain is a mixture of picric acid and acid fuchsin. It is the simplest method of differential staining of collagen and other connective tissue. It was introduced to histology by American neuropsychiatrist and pathologist Ira Van ...
stain aids in diagnosis of
giant cell arteritis
Giant cell arteritis (GCA), also called temporal arteritis, is an inflammatory autoimmune disease of large blood vessels. Symptoms may include headache, pain over the temples, flu-like symptoms, double vision, and difficulty opening the mouth. ...
. It stains
muscle tissue in yellow,
connective tissue in red and elastic structures (like internal elastic lamina) in black color.
[
* In chronic allograft nephropathy, disruption or reduplication of internal elastic lamina can be observed, which causes narrowing of the lumen and downstream ischemia.
* In fungal ]rhinosinusitis
Rhinosinusitis is a simultaneous infection of the nasal mucosa (rhinitis) and an infection of the mucosa of the paranasal sinuses ( sinusitis). A distinction is made between acute rhinosinusitis and chronic rhinosinusitis.
Background
Because sin ...
, the organism has predilection for internal elastic lamina during phase of spread.
References
Angiology
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