suggests that each of the blood cell lineages is derived from its own unique stem cell.

Chief site of hematopoietic activity: yolk sac and then progresses in the aorta-gonad-mesonephros (AGM) region

Begins at 5 to 7 gestational weeks and is characterized by recognizable clusters of developing erythroblasts, granulocytes, and monocytes colonizing the fetal liver, thymus, spleen, placenta, and ultimately the bone marrow space in the final medullary phase.

Predominant hemoglobin

Hematopoiesis in the bone marrow (termed as medullary hematopoiesis)

Transcribe HSC

Major site of T cell production

Produces B cells

Transcribe EPO

Bones of fromation of blood cells, except:

One of the largest organs in the body, is located within the cavities of the cortical bones.

Projections of calcified bone

hematopoietically active marrow that is composed of developing blood cells and their progenitors

Hematopoietically inactive marrow composed primarily of adipocytes (fat cells), with undifferentiated mesenchymal cells and macrophages.

The process of replacing the active marrow by adipocytes (yellow marrow) during development

Transcribe ASC

Ratio of myeloid to erythroid

The ratio of red marrow to yellow marrow is termed as

Originate from mesenchymal cells that migrate into the central cavity of the bone

Broad, flat cells that form a single continuous layer along the inner surface of the arteries, veins, and vascular sinuses

Large cells with a sigle fat vacuole; regulates the volume of the marrow in which active hematopoesis occur

Develop in small clusters and more mature forms are located adjacent to the outer surfaces of the vascular sinuses

Facilitates the release of platelets into the lumen of sinus.

Stage are located deep within the cords

Plays an important role in nurturing and protecting HSCs and regulating their quiescence, self-renewal, and differentiation.

Macrophages that remove senescent cells and foreign debris from blood that circulates through the liver.

Production of various blood cells in the liver

Hereditary or acquired defects in the enzymes involved in heme biosynthesis

Largest lymphoid organ in the body

Consists of scattered follicles with germinal centers containing lymphocytes, macrophages, and dendritic cells.

Cords of billroth synonym

Cells are phagocytized with subsequent degradation of cell organelles

Splenic macrophages remove inclusions or damaged surface membrane from circulating RBCs.

Enlargement of spleen resulting in some degree of pancytopenia despite the presence of a hyperactive bone marrow.

Removal of spleen

Marrow has 30-70% hematopoietic cells

Marrow has > 70% hematopoietic cells

Marrow has < 70% hematopoietic cells

Marrow has no hematopoietic cells