Functional grammar is a linguistic theory that states all constituents, whether affixes, words, phrases, or sentences, have semantic, syntactic, and pragmatic functions.Functional grammarians can classify linguistics as semantic, pragmatic, morphosyntactic, or phonological.he most famous of these is Systemic Functional Grammar, which was first published by British linguist Michael Halliday in 1961. Other functional grammars include Danish Functional Linguistics, lexical functional grammar, and Role and Reference Grammar.
hematopoiesis. the formation and development of blood cells, usually taking place in the bone marrow. cyclic hematopoiesis of collies. see canine cyclic hematopoiesis.[hÄâ²mÉtÅpÅÂ·Äâ²sis, hemâ²-]. Etymology: Gk, haima + poiein, to make. the normal formation and development of blood cells in the bone marrow. In severe anemia and other hematologic disorders, cells may be produced in organs outside the marrow (extramedullary hematopoiesis).xtramedullary hematopoiesis. the formation of and development of blood cells outside the bone marrow, as in the spleen, liver and lymph nodes. fetal hematopoiesis. in embryogenesis migration of stem cells from the yolk sac blood islands sets up hematopoiesis in thymus, lymph nodes, liver and spleen.
The hematopoietic component of bone marrow produces approximately 500 billion blood cells per day, which use the bone marrow vasculature as a conduit to the body's systemic circulation. Bone marrow is also a key component of the lymphatic system, producing the lymphocytes that support the body's immune system.n humans, red blood cells are produced by cores of bone marrow in the heads of long bones in a process known as hematopoiesis. On average, bone marrow constitutes 4% of the total body mass of humans; in an adult weighing 65 kilograms (143 lb), bone marrow typically accounts for approximately 2.6 kilograms (5.7 lb).