An analogous formula applies to the case of a continuous probability distribution. Not every probability distribution has a defined mean; see the Cauchy distribution for an example. Moreover, for some distributions the mean is infinite: for example, when the probability of the value is for n = 1, 2, 3, ....
Red blood cell (RBC) production (erythropoiesis) takes place in the bone marrow under the control of the hormone erythropoietin (EPO). Juxtaglomerular cells in the kidney produce EPO in response to decreased O 2 delivery (as in anemia and hypoxia) and increased levels of androgens.
Bone marrow is found inside the bones, and it functions to produce the body's blood cells through a process called hematopoiesis. Bone marrow comes in two types: red marrow and yellow marrow. Within the red bone marrow, red blood cells, white blood cells and platelets are manufactured.