Stroma(redirected from stromas)
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(1) The supporting framework of an animal organ. The stroma consists of unstructured connective tissue containing specific elements of an organ, cells capable of reproduction, and fibrous structures that provide support. Blood vessels and lymphatics pass through it. Stromal elements perform a protective role by participating in phagocytosis. Red and white blood cells develop from the stromal cells of hematopoietic organs.
(2) The protein base of erythrocytes.
(3) In many ascomycetes and Fungi Imperfecti, the compact mass of hyphae upon which spore-bearing bodies (conidio-phores) are arranged.
(4) In algae and higher plants, the colorless protein base of plastids in which a strictly ordered system of membranes serving as pigment carriers is embedded.