Hematopoiesis Flashcards
(46 cards)
Process of blood cell formation
Hematopoiesis / Hemopoiesis
Classical marker of hematopoietic stem cells
CD 34
When does Hematopoiesis start ?
19th Day of embryonic development following fertilization
1st blood cell formed during the first 2-8 weeks of life
Primitive erythroblasts
Hemoglobin in primitive erythroblasts
Gower 1, Gower 2, Portland
First fully developed organ in the fetus
Thymus
Predominant Hemoglobin in Hepatic phase of Hematopoiesis
Hb F
What are the three phases of hematopoiesis
- Megaloblastic / Mesoblastic
- Hepatic
- Myeloid / Intermedullary / Medullary
Process of replacing red marrow by yellow marrow during development (between 5-7 years of age)
Retrogression
Situations wherein yellow marrow can revert back to its active state
Hemolysis and excessive blood loss
Site wherein Red marrow and Yellow marrow can be seen
RSVP Ribs Sternum Vertebrae Pelvis and Proximal ends of the long bones
In adults there is approximately _ % of yellow marrow and _ % of red marrow
50: 50
Hematopoietically active marrow
Red marrow
Prevalent cells in the yellow marrow
Adipocytes
Primary lymphoid organs
Bone marrow and thymus
Major secondary lymphoid organs
Spleen and Lymph nodes
Largest secondary lymphoid organ
Spleen
Increased hemolytic activity of the spleen caused by splenomegaly
Hypersplenism
Responsible for extramedullary Hematopoiesis as response to infectious agents or in pathologic myelofibrosis
Liver and Spleen
Preferred site for BM aspiration in adults
Posterior / Anterior superior iliac crest
Preferred site for BM aspiration in children less than 2 years of age
Tibia
Normal M:E ratio in adults
myeloid: erythroid
2:1 to 4:1
M:E ratio of patients with leukemia
10:1
Recommended cells to be counted in the marrow differential
At least 500 cells * preferably 1,000 cells
