peruskalvosta

Peruskalvo, or basement membrane, is a thin, specialized extracellular matrix that lies between epithelial or endothelial cells and the underlying connective tissue. It provides structural support and helps organize tissues. In Finnish scientific usage, peruskalvo refers to this basal, substrate-like layer that accompanies many epithelia and endothelia.

The basement membrane consists of two main components: the basal lamina and the reticular lamina. The basal lamina is primarily secreted by epithelial or endothelial cells and contains laminin, type IV collagen, nidogen (entactin) and proteoglycans such as perlecan. The reticular lamina is produced by surrounding connective tissue and contains other collagens, including type III collagen. In some tissues, the basal lamina can be further described in terms of layers, such as lamina rara and lamina densa.

Functions of the peruskalvo include providing mechanical support, guiding tissue organization, and regulating cell behavior. It acts as a selective filtration barrier in organs like the kidney, influences cell adhesion, migration, and differentiation via receptors such as integrins, and participates in wound healing and development by signaling to resident cells. The basement membrane also plays a role in maintaining tissue integrity and polarity.

Clinical and physiological relevance is seen when the peruskalvo is altered. Thickening or structural changes occur in diabetic nephropathy and other kidney diseases; autoimmune diseases such as bullous pemphigoid involve antibodies against basement membrane components; and tumor cells must traverse the basement membrane during invasion and metastasis. Peruskalvo is a key feature in histology of many organs, including skin, intestine, and kidney.