2. Hematopoiesis Flashcards
What is hematopoiesis ?
Production and differentiation of blood cells
What is the classical marker for hematopoietic stem cells ?
CD 34
The classical marker for hematopoietic stem cell CD 34 is also known as ?
Pluripotential cell (Mother cell)
What is the Polyphyletic theory ?
This theory suggests that each of the blood cell lineages is derived from its own unique stem cell
What is the Monophyletic theory ?
This theory suggests that all blood cells are derived from a single progenitor stem cell called a pluripotential stem cell
Under the Monophyletic theory hematopoiesis involves the production of ___ that develop into committed ___ and finally ___
pluripotential stem cells -> progenitor cells (lymphoid or myeloid) -> mature blood cells
What does CFU-GEMM stand for ?
colony forming unit granulocyte erythrocyte macrophage megakaryocyte
What are the three phases of hematopoiesis ?
Mesoblastic/Megaloblastic -> Hepatic -> Medullary/Myeloid
When does the mesoblastic phase of hematopoiesis begin ?
~19 days gestation
What is the chief site of hematopoiesis during the mesoblastic phase ?
yolk sac
When are the primitive nucleated erythroblasts formed during the mesoblastic phase ?
first 2 - 8 weeks of life
What is the function of primitive nucleated erythroblasts ?
give out hemoglobin to satisfy the oxygen needs of the fetus
What are the embryonic hemoglobin’s produces during the mesoblastic phase ?
Portland, Gower I, and Gower II
When does the hepatic phase of hematopoiesis begin ?
6 weeks of gestation
What is the chief site of hematopoiesis during the hepatic phase ?
liver
What is produced during the hepatic phase ?
mainly red blood cells, also granulocytes, monocytes, and megakaryocytes
Hgb F; detectable Hgb A and A2
When does the medullary phase of hematopoiesis begin ?
5th month of gestation
What is the chief site of hematopoiesis during the medullary phase ?
bone marrow
What does mainly red marrow indicate in a bone marrow ?
very active blood cell production
The main sites of adult hematopoiesis is confined to the proximal ends of large flat bones which are ___
Ribs, sternum, vertebrae, pelvis
What is the most common bone marrow collection site ?
Posterior superior iliac crest
What are the indications for bone marrow examination ?
Neoplasia diagnosing and staging Marrow failure: cytopenias Metabolic disorders Infections Monitoring and treatment
What is marrow cellularity ?
ratio of marrow cells to fat
Normocellular marrow has a ___% hematopoietic cells
30-70%
