trabecular

Trabecular is an adjective used in anatomy and histology to describe a network of small beam-like elements (trabeculae) that form a supporting lattice within a tissue. The word derives from Latin trabecula, meaning a small beam. The term is used across several organ systems to denote a porous, structured framework rather than a solid mass.

In bone, trabecular, or cancellous bone, consists of thin trabeculae arranged in a porous network that fills the interior of bones such as the vertebrae and the ends of long bones. The spaces contain bone marrow and contribute to the bone’s light weight while maintaining strength. The lattice provides resistance to multidirectional stresses and increases surface area for metabolic activity, including mineral exchange and remodeling. The architecture adapts to mechanical load (Wolff’s law) and is maintained by bone-forming osteoblasts and bone-resorbing osteoclasts. Diseases such as osteoporosis reduce trabecular thickness and connectivity, raising fracture risk. On imaging, trabecular bone appears as a latticework of porous structures, contrasting with the outer cortical shell.

In the eye, the trabecular meshwork is a sieve-like tissue at the iridocorneal angle through which aqueous humor drains into Schlemm’s canal and the venous system. Its function helps regulate intraocular pressure. Impaired drainage can lead to elevated pressure and glaucoma. Treatments include topical medications, laser procedures such as laser trabeculoplasty, and surgical approaches aimed at improving outflow.

The term is also used to describe lattice-like arrangements in other organs, including trabeculae in the liver and spleen, where interconnected cords and plates provide structure and facilitate function.