Glomerular basement membrane

Glomerular Basement Membrane

File:Glomerulus.png

Illustration of a Glomerulus, including the Glomerular Basement Membrane

The Glomerular Basement Membrane (GBM) is a crucial part of the kidney's filtration system, known as the glomerulus. It serves as a physical barrier in the filtration of blood, allowing certain substances to pass through while blocking others.

Structure

The GBM is composed of three layers: the lamina rara externa, the lamina densa, and the lamina rara interna. These layers are primarily made up of Type IV collagen, laminin, heparan sulfate, and entactin. The unique composition and structure of the GBM allow it to perform its filtration function effectively.

Function

The primary function of the GBM is to filter blood. It allows water, ions, and small molecules to pass through while preventing the passage of larger molecules such as proteins. This selective permeability is crucial for the maintenance of homeostasis in the body.

Clinical Significance

Abnormalities in the GBM can lead to various kidney diseases. For instance, Goodpasture syndrome is an autoimmune disease where antibodies attack the collagen in the GBM, leading to kidney failure. Alport syndrome, a genetic disorder, also affects the GBM and can cause progressive kidney damage.

See Also

• Kidney
• Glomerulus
• Goodpasture syndrome
• Alport syndrome