FETAL HEMATOPOIESIS (PHASES)

Question 1

Site of hematopoiesis in adults

Answer 1

RESTRICTLY IN THE BONE MARROW

Question 2

3 phases in fetal hematopoiesis

Answer 2

Mesoblastic phase
Hepatic Phase
Medullary phase

Question 3

MESOBLASTIC PHASE

Answer 3

• at 19th day of embryonic development

* cells from mesoderm move to the yolk sac

Question 4

WHAT HGB does mesoblastic phase produces

Answer 4

PRIMITIVE RBC- MEGALOBLAST OF EHRLICH

Gower-1. Gower-2, and Portland needed for delivery of oxygen to rapidly developing embryonic tissues

Question 5

HEPATIC PHASE

Answer 5

begins at 5-7 gestational weeks
cluster of RBCs, granulocytes and monocytes in the liver thymus, spleen placenta and bone marrow.
Hematopoiesis is EXTRAVASCULAR
Megakaryocyte production begins as well

Question 6

major site of hematopoeisis is hepatic phase

Answer 6

LIVER, reaches it peak in 3rd month of fetal development. Minimal activity @ 1-2 weeks after birth

Question 7

second site of hematopoiesis in hepatic phase

Answer 7

SPLEEN & KIDNEY- BCELLS

THYMUS- TCELLS

Question 8

prominent/ predominant hgb in hepatic phase

Answer 8

FETAL HEMOGLOBIN/ HGB F, however detectable levels of Hb A (adultd hgb) may be present

Question 9

MEDULLARY (MYELOID) PHASE

Answer 9

starts prior to 5th moth of fetal development.
occurs in the inner or medullar part of the bone
The end of 24 weeks gestation, BONE MARROW is the primary site of hematopoiesis

Question 10

CELLS FOUND IN MEDULLARY PHASE

Answer 10

asurable levels of erythropoietin (EPO), granulocyte colonystimulating factor (G-CSF), granulocyte-macrophage colonystimulating factor (GM-CSF), and hemoglobins F and A can be
detected.8 In addition, cells at various stages of maturation can
be seen in all blood cell lineages.