HEMA W3:1 Flashcards
Continuous regulated process of renewal, proliferation, differentiation, and maturation of all blood cell lineages.
HEMATOPOIESIS
The process results in the formation, development, and specialization of all functional blood cells.
HEMATOPOIESIS
capable of self-renewal and directed differentiation into all required lineages
Hematopoietic stem cell
PHSC
Pluripotential hematopoietic stem cell
have they respective lifespans and a cell population capable of self-renewal that sustains the system.
Mature blood cells
Phases of Primitive hematopoiesis
Mesoblastic, Hepatic, and Medullary phase
Begins around 19th day of embryonic development after fertilization, cells from mesoderm
migrates to the yolk sac producing blood cells that lasts until the 8th to 12th week of gestation
Mesoblastic phase
Hematopoietic activity is confined only to ERYTHROPOESIS
Mesoblastic phase
Blood produced in this phase that is found in the central cavity of yolk sac
together with angioblast that surrounds the yolk sac forming blood vessels
Primitive erythroblasts
Important in early embryogenesis to produce embryonic hemoglobin
Primitive erythroblasts
Important in early embryogenesis to produce embryonic hemoglobin
Primitive erythroblasts
Embryonic hemoglobin
Gower-I hemoglobin:
Gower-II hemoglobin:
Portland hemoglobin:
Gower-I hemoglobin
2 epsilon, 2 zeta globin chains
Gower-II hemoglobin
2 epsilon, 2 alpha globin chains
Portland hemoglobin
2 zeta, 2 gamma globin chains
As yolk sac declines in producing blood cells, fetal liver takes charge that starts from 5
th to 7th
week of gestation until the 1st or 2nd week of life
Hepatic phase
Remains as primary site of production until 6th months of gestation
Hepatic phase
Characterized by recognizable clusters of developing erythroblasts, granulocytes, monocytes colonizing liver, thymus, spleen, placenta and eventually bone marrow
Hepatic phase
3rd month of gestation
Definitive erythroblast
3rd month of gestation
Granulocytes and megakaryocytes
4th month of gestation
Lymphocytes
5th month of gestation
Monocytes
Hemoglobin formed during hepatic phase
Fetal hemoglobin (Hgb F):
Adult hemoglobin (Hgb A)
Adult hemoglobin (Hgb A)
Hemoglobin A1:
Hemoglobin A2:
Fetal hemoglobin (Hgb F)
2 alpha, 2 gamma globin chains
Hemoglobin A1
2 alpha, 2 beta globin chains
Hemoglobin A2
2 alpha, 2 delta globin chains
Hematopoietic activity found in the medulla cavity of the bone cavity and begins at 4th to 5
th month of fetal development and continues towards adulthood
Medullary phase
main site of hematopoiesis by the end of 24th weeks of gestation
Red bone marrow
______ cells start to support developing hematopoietic elements having an observable
myeloid-to-erythroid activity and balance
Mesenchymal
Normal myeloid-to-erythroid activity
3:1 to 4:1
Indication of infection in myeloid-to-erythroid activity
6:1
Indication of leukemia in myeloid-to-erythroid activity
25:1
Growth factors that are required for medullary phase to differentiate blood cells
Erythropoietin (EPO)
Granulocyte colony stimulating factor (G-CSF)
Granulocyte-Macrophage colony stimulating factor (GM-CSF)
Hemoglobin formed in medullary phase
Fetal hemoglobin:
Adult hemoglobin:
predominant in newborn
Fetal hemoglobin in medullary phase
predominant in adult
Adult hemoglobin in medullary phase
