Intellectual disability, also known as mental retardation, is a term used when there are limits to a personâs ability to learn at an expected level and function in daily life.Levels of intellectual disability vary greatly in children â ï·from a very slight problem to a very severe problem.ntellectual disability can be caused by a problem that starts any time before a child turns 18 years old â even before birth. It can be caused by injury, disease, or a problem in the brain. For many children, the cause of their intellectual disability is not known.
Hemopoiesis. Definition. noun. A biological process in which new blood cells are formed, and is usually taking place in the bone marrow. Supplement. All cellular components of the blood came from hematopoietic stem cells (HSCs) located in the marrow. The HSCs have the ability to give rise to all of the different mature blood cell types, such as erythrocytes, T cells, B cells, granulocytes, megakaryocytes, macrophages.
Diagram showing the development of different blood cells from haematopoietic stem cell to mature cells. Haematopoiesis (from Greek Î±á¼·Î¼Î±, blood and ÏÎ¿Î¹Îµá¿Î½ to make; also hematopoiesis in American English; sometimes also haemopoiesis or hemopoiesis) is the formation of blood cellular components.hen bone marrow develops, it eventually assumes the task of forming most of the blood cells for the entire organism. However, maturation, activation, and some proliferation of lymphoid cells occurs in secondary lymphoid organs (spleen, thymus, and lymph nodes).