Haemopoiesis Flashcards
what is haemopoiesis?
the formation of blood cells
what is erythropoiesis?
the formation of red cells
what is thrombopoiesis?
the formation of platelets
what is the most common type of blood cell?
red blood cell
what is the average lifespan of a red cell?
120 days
what is the average lifespan of a neutrophil?
7-8 hours
what is the average lifespan of a platelet?
7-10 days
state the steps of development of a red cell
pronormoblast
early/intermediate/late normoblast
reticulocyte
erythrocyte
state the steps in development of a neutrophil
myeloblast promyelocyte myelocyte metamyelocyte band neutrophil mature neutrophil
what is the immediate precursor of a platelet?
megakaryocyte
what is a “-blast”?
a nucleated precursor cell
what is the immediate red cell precursor?
reticulocytes
what are myelocytes?
the nucleated precursor cell between a neutrophil and a white cell blast
where do all hematopoietic cells originate?
from the hematopoietic stem cells
where do haematopoietic stem cells originate embryonically?
in the mesoderm
what is the first site of erytrhoid activity?
the yolk sac
when does the yolk sac lose haematopoietic activity?
by week 10
when does the liver begin haemopoiesis?
week six
when does the bone marrow start haemopoiesis?
by week sixteen
what bones in an adult contain bone marrow that can undergo haemopoiesis?
axial skeleton
pelvis
proximal long bones
where is a bone marrow biopsy taken in an adult?
posterior iliac crest
sternum
where is a bone marrow biopsy taken in a young child?
tibia
what non haematopoietic cells are found in the bone marrow?
adipocytes
fibroblasts
osteoclasts
osteoblasts
what are the two types of bone marrow?
red = haematopoietically active
yellow marrow = fatty and inactive
what type of marrow increases with age and what does this cause?
yello wmarrow
reduced marrow cellularity
what is a normal range for the myeloid:erythroid ratio?
1.5-3.3 : 1
what regulates neutrophil precursor maturation?
G-CSF
granulocyte colony stimulating factor
what regulates growth of megakaryocytes from their precursors?
thrombopoietin
what routine investigations can be done to assess haemopoiesis in non-lymphoid mature cells?
blood counts
cell indices
blood film
what is immunophenotyping?
using antibodies to identify a pattern of antigen expression unique to a cell lineage
what tests can be done to assess morphologically indistinguishable cells?
immunophenotyping
clonogenic assays
animal models
