Microvillus Border of Simple Cuboidal Epithelium of Proximal Convoluted Tubule
Lumbus microvillosus
Read moreQuick Facts
A microvillus border is a specialization of the free surface of certain cells, consisting of minute cylindrical processes (microvilli) that greatly increase the surface area; in vertebrates these are found especially on the cells of the proximal convoluted tubules of the kidney and on the intestinal epithelium (Dorland, 2011).
Structure and/or Key Feature(s)
Cuboidal epithelial cells line this tubule and exhibit elaborate surface specializations to enhance the major functions of the tubule which are reabsorption and fluid transport. These specializations include:
—a “brush border” characterized by long, straight and closely packed microvilli;
—a junctional complex that prevents continuity between the intercellular space and tubule lumen;
—zonula adherens, which establish strong adhesion between adjacent cells;
—significant folding and interdigitations of both lateral and basal plasma membrane of the adjacent cell;
—basal striations, which appear as elongated, vertically oriented mitochondria accumulate at the basal surface of the cells (Ross and Pawlina, 2006).
Anatomical Relations
The microvillus border is an elaborate surface specialization on cuboidal epithelial cells of the proximal convoluted tubule.
Function
Microvilli on the cuboidal epithelial cells of the proximal convoluted tubule greatly increase the surface area for more effective absorption of fluid.
References
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
Ross, M. H. and Pawlina, W. (2006) Histology: A text and atlas. Lippincott Williams & Wilkins.
