Alterations in Myeloid:Erythroid Ratio

           The M:E ratio is sensitive to hematologic factors that may impair red blood cell life span, inhibit overall production, or cause dramatic increases in a particular cell line. Each of these conditions reflects bone marrow dynamics through alterations of the M:E ratio. Many observations...

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Bone Marrow & Myeloid:Erythroid Ratio

           The bone marrow is one of the largest organs of the body, encompassing 3% to 6% of body weight and weighing 1500 g in an adult. It is hard to conceptualize the bone marrow as an organ because it is not a solid organ that one can touch, measure, or weigh easily. Because bone marrow tissue...

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Thymus

          The thymus is a lymphopoietic organ located in the upper part of the anterior mediastinum. It is a bilobular organ demarcated into an outer cortex and central medulla. The cortex is densely packed with small lymphocytes (thymocytes), cortical epithelial cells, and a few macrophages. The medulla is less...

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Extramedullary Hematopoiesis

           Hematopoiesis in the bone marrow is called medullary hematopoiesis or intramedullary hematopoiesis.    Blood cell production in hematopoietic tissue other than bone marrow is called extramedullary hematopoiesis.    In certain hematologic disorders when hyperplasia...

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Sites of Hematopoiesis

      Hematopoiesis/Hemopoiesis is the process by whitch blood cells are formed.  Sites of Hematopoiesis Yolk sac      From the 18th day after fertilization, the yolk sac begins hematopoiesis. The cells made here are erythrocytes & few macrophages. Aorta-gonads-mesonephros (AGM) region     ...

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Functions of the Spleen

Hematopoietic function:- Can produce white blood cells, red blood cells, and platelets if necessary. Reservoir function:- One-third of platelets and granulocytes are stored in the spleen. Filtration functions:- Aging red blood cells are destroyed. Spleen removes inclusion from red blood cells. If red blood cell membrane is less deformable...

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Lineage-specific Cytokine Regulation

LINEAGE-SPECIFIC CYTOKINE REGULATION Erythropoiesis: In the erythroid lineage, progenitor cells give rise to two distinct types of erythroid colonies in culture. A primitive progenitor cell, the BFU-E, is relatively insensitive to EPO and forms large colonies after 14 days in the form of bursts. Production of BFU-E colonies was originally described...

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Cytokines and the Control of Hematopoiesis

Hematopoietic growth factor cytokines are specific glycoproteins that regulate and control hematopoiesis. Functions of hematopoietic growth factor cytokines:-  Promote cell survival (suppress apoptosis).  Promote proliferation.  Control & regulate the processes of differentiation. Characteristics of Growth Factors:- Produced...

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