Bone MarrowThe functional role of the bone marrow in blood cell production depends on both its structural and cellular competence. This is supported by the following evidence:
[1] Donor stem cells given intravenously to a bone marrow transplant recipient will home in on the "empty" marrow and repopulate the patient's marrow with healthy haemopoietic tissue.
[2] Marrow damaged by radiation may never regain haemopoietic ability, because the cells which support blood cell production have been destroyed.
Stem cells are bound with in the bone marrow and are the origin of all blood cells. Blood cells are formed by the process of differentiation from the least developed stem cell to a highly specialized blood cell.
[1] Pluripotential stem cells are the least developed stem cells isolated in human marrow cultures. Morphologically these cells resemble small lymphocytes. They are called colony-forming units-blast (CFU-B) and have the ability to generate mixed colonies of progenitor cells.
[2] Multipotential stem cells develop from the differentiation of pluripotential stem cells. They are the ancestor cells for either lymphoid or myeloid cell lines. Lymphoid multipotential stem cells give rise to two lines of progenitor cells from which developed B (bone marrow) and T (thymus) dependent lymphocytes. Myeloid multipotential stem cells give rise to colonies of erythroid, granulocytic, monocytic, and megakaryocytic progenitor cells, from which develop precursor cells and eventually mature red cells, neutrophils, eosinophils, monocytes, and platelets.
Title : Bone Marrow
Description : Bone Marrow The functional role of the bone marrow in blood cell production depends on both its structural and cellular competence. This is ...
