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 in ...

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 An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts o ...

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 prima ...

, 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 Smooth muscle is an involuntary non- striated muscle, so-called because it has no sarcomeres and therefore no striations (''bands'' or ''stripes''). It is divided into two subgroups, single-unit and multiunit smooth muscle. Within single-unit ...

cells in their

, 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 The basement membrane is a thin, pliable sheet-like type of extracellular matrix that provides cell and tissue support and acts as a platform for complex signalling. The basement membrane sits between epithelial tissues including mesothelium and ...

of endothelial cells and internal elastic lamina. Reduplication of internal elastic lamina can be seen in elderly individuals due to intimal fibroplasia, which is part of the

aging Ageing ( BE) or aging ( AE) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In ...

process.

Associated pathologic conditions

*Damage in Giant cell arteritis leads to microaneurysms. Demonstration of fragmentation in this layer by elastin- van Gieson stain aids in diagnosis of giant cell arteritis. It stains

muscle Skeletal muscles (commonly referred to as muscles) are Organ (biology), organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other ...

tissue in yellow,

connective tissue Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tissue ...

in red and elastic structures (like internal elastic lamina) in black color. * In

chronic allograft nephropathy Chronic allograft nephropathy (CAN) is a kidney disorder which is the leading cause of kidney transplant failure, occurring months to years after the transplant. Symptoms and signs CAN is characterized by a gradual decline in kidney function and, ...

, disruption or reduplication of internal elastic lamina can be observed, which causes narrowing of the lumen and downstream ischemia. * In fungal rhinosinusitis, the organism has predilection for internal elastic lamina during phase of spread.

References

Angiology {{circulatory-stub