Sidekudoskerros

Sidekudoskerros is a Finnish term that denotes a layer of connective tissue, typically understood as loose connective tissue or areolar tissue. In anatomical usage it describes a tissue layer that lies between epithelial surfaces and deeper structures, and that envelopes small vessels, nerves, and organs. Its main roles are to support, bind, and cushion tissues while permitting the diffusion of nutrients, gases, and waste products between blood vessels and surrounding cells.

The tissue is characterized by a relatively loose arrangement of cells and fibers within a gel-like extracellular matrix. The cellular component includes fibroblasts, macrophages, mast cells, adipocytes, and various immune cells. The extracellular matrix contains collagen fibers (primarily types I and III), elastin, and a ground substance rich in glycosaminoglycans and proteoglycans. Because of its loose organization, sidekudoskerros allows for pliability and movement of tissues relative to one another and often hosts a network of small blood vessels.

Distribution varies by region and function. It is commonly found beneath epithelia in the skin and mucous membranes and around form pathways such as ducts and nerves. In some areas, it blends into certain specialized connective tissues and contributes to organ architecture by wrapping around glands, vessels, and nerve trunks. Clinically, its quality and thickness can influence edema, inflammatory responses, and tissue healing, with regional variations in density affecting diffusion and mechanical properties.

In common terminology, sidekudoskerros is frequently equated with areolar tissue or subepithelial connective tissue, though exact naming can depend on anatomical context and location.