retikulaarne

Retikulaarne, Estonian for “reticular” or “net-like,” is a descriptive term used in biology and medicine to denote structures that form a fine, branching mesh. In histology it refers to tissues and fibers arranged in a lattice rather than in parallel bundles, creating a supportive framework for other cells.

A central application is reticular connective tissue, which consists of reticular fibers and reticular cells. Reticular fibers are thin, delicate fibers primarily made of type III collagen. They branch to form a three-dimensional network that provides structural support (stroma) for parenchymal cells. This network is especially important in lymphoid organs and hematopoietic sites.

Key locations where reticular tissue is prominent include the bone marrow, spleen, liver, and lymph nodes, where the reticular mesh supports immune and blood-forming cells. Reticular tissue also appears in some organs and glands as a supporting scaffold for delicate cellular arrangements.

In microscopy, reticular fibers are often visualized with silver-based reticulin stains, which highlight the meshwork, or with specific immunohistochemical markers for collagen type III. The presence and integrity of the reticular network are important for organ architecture and cellular organization, influencing processes such as hematopoiesis and immune cell trafficking.

Etymology derives from Latin reticulum, meaning “little net.” In Estonian medical usage, retikulaarne is the adjective form describing such net-like structures.