reticular1

Resembling a net.

• r. activating system — the system of cells of the reticular formation of the medulla oblongata that receive collaterals from the ascending sensory pathways and project to higher centers; they control the overall degree of central nervous system activity, including wakefulness, attentiveness and sleep; abbreviated RAS. Called also ascending reticular formation.
• ascending r. formation — see reticular activating system (above).
• r. cells — stellate cells that form the reticular fibers of connective tissue; they form the supporting framework of bone marrow, lymph nodes, lymphatic nodules, spleen and tonsils.
• r. colliquation, epidermal r. degeneration — severe intracellular edema of epidermal cells, characterized by the degeneration of cells to form reticulated septa separating lobules of fluid.
• descending r. system — a diffuse motor control mechanism which descends from the midbrain to lower motor neurons in the brainstem and spinal cord.
• r. dysgenesis — a congenital error in stem cell numbers in the bone marrow; a rare cause of anemia.
• r. formation — see ascending reticular formation, reticular activating system (above).
• medullary r. formation — see ascending reticular formation (above).
• r. tissue, reticulated tissue — connective tissue composed predominantly of reticulum cells and reticular fibers.