The Development of Red Blood Cells

The development of red blood cells is a function of great importance to the organism. What the restoration of a sufficient number of erythrocytes may mean to the body when its circulation has been seriously depleted by hemorrhage or blood-destroying disease is obvious. If it happens, as is currently believed, that a physiologic destruction of red blood cells is proceeding in some degree even in health, their replacement belongs to the continuous normal activities of the hematopoietic tissues. To locate their function in the bone marrow or spleen gives only an incomplete suggestion of what the process may be. There has been considerable embryologic evidence that in the earliest stages of the development of the organism the red cells of the blood differentiate intravascularly. For the adult bone marrow it has been taught, on the other hand, that there is a different type of genesis. Thus, the belief that the erythrocytes develop there in extravascular clumps has been so generally accepted that investigators have labored assiduously to discover how the mature red cells formed in this manner make their way into the blood stream. Studies conducted in the Department of Anatomy at the Johns Hopkins University on the bone marrow of both birds and mammals seem destined to present the problem in a new light. When this structure is largely depleted of its myelocytes by suitable procedures and has not yet begun to form new white cells to any appreciable extent, the endothelial membranes ...
Source: JAMA - Category: General Medicine Source Type: research