Limiting membrane

Limiting Membrane is a term used in various fields of biology and medicine to describe a thin layer or boundary that restricts or controls the movement of substances. Depending on the context, it may refer to different structures in the body, such as the basement membrane, the internal elastic lamina, or the retinal pigment epithelium.

Basement Membrane

The basement membrane is a type of limiting membrane that separates epithelial or endothelial cells from the underlying connective tissue. It is composed of two layers: the basal lamina, produced by the epithelial cells, and the reticular lamina, produced by the connective tissue cells. The basement membrane plays a crucial role in tissue repair, filtration, and cell adhesion.

Internal Elastic Lamina

The internal elastic lamina is a limiting membrane found in arteries. It separates the tunica intima, the innermost layer of an artery, from the tunica media, the middle layer. The internal elastic lamina is rich in elastin, a protein that allows tissues to resume their shape after stretching or contracting.

Retinal Pigment Epithelium

The retinal pigment epithelium (RPE) is a limiting membrane in the eye. It forms the outermost layer of the retina and plays a vital role in visual function. The RPE transports nutrients from the blood to the photoreceptor cells, absorbs excess light to prevent scattering, and regenerates the visual pigment rhodopsin.

See Also

• Cell membrane
• Epithelium
• Endothelium
• Connective tissue
• Artery
• Retina
• Photoreceptor cell
• Rhodopsin