Areolar

Areolar tissue, or areolar connective tissue, is a type of loose connective tissue that forms part of the body's structural framework. It consists of a loose, three-dimensional mesh of collagen and elastic fibers embedded in a viscous ground substance, with a variety of cells such as fibroblasts, macrophages, mast cells, and plasma cells. The fibers are loosely arranged, giving the tissue a spongy, permeable texture that supports other tissues while allowing diffusion of nutrients and waste.

Distribution and function: Areolar tissue is widely distributed, lying beneath epithelia in the skin and mucous membranes, and forming part of the dermis and lamina propria. It surrounds blood vessels, nerves, glands, and organs, binding them to surrounding tissues. The loose matrix provides cushioning, enables movement of structures, and acts as a reservoir for interstitial fluid. It also participates in immune responses by housing immune cells and releasing mediators during inflammation.

Clinical notes and terminology: Areolar tissue is distinct from adipose tissue and from dense connective tissues such as tendons and ligaments. The word areolar derives from the Latin areola, meaning a small open space or net, reflecting its airy, networked appearance under the microscope.