how blood is made (hematopoiesis)

where are blood cells made

bone marrow

medullary hematopoiesis

hematopoiesis that occurs in bone marrow

when are blood cells released into the bloodstream

once they are mature

where can blood cells also be made?

liver and spleen

hematopoiesis in the liver and spleen

extramedullary hematopoiesis

what kind of feedback mechanism controls the production of blood?

negative feedback mechanism; production is driven by tissue oxygen levels

describe what controls the production of blood cells

when oxygen delivery is low due to low red blood cell count, the kidneys and liver increase production of the hormone erythropoietin that stimulates bone marrow to produce more blood cells

what are the steps of red blood cell production

start off as stem cells, turn into common myeloid progenitor cells, proerythroblast, erythroblast, reticulocyte, ertyrhocyte

how do all blood cell start off?

as hematopoietic stem cells

what do hematopoietic stem cells turn into

common myeloid progenitor cells (CMP)

megakaryocyte erythroid progenitor cells (MEP)

common myeloid progenitor cells (CMP) that become red blood cells; they move through the next stages of red blood cell production

proerythroblast

hemoglobin begins to form during this stage, proerythroblasts multiply to make more cells which have a nucleus

erythroblast (or normoblasts)

cells continue to divide and produce hemoglobin

reticulocyte

immature red blood cells lose their nuclei and move into the bloodstream

erythrocyte

final stage where mature red blood cells can carry oxygen