Hematopoiesis Flashcards
Where does hematopoiesis take place at 1st trimester, 2nd trimester, and 3rd trimester
1st - fetus (yolk - sack)
2nd - liver
3rd - bone marrow
What are the two main sites for hematopoiesis after birth till 25
Long bones (tib/fib)
What are the three main sites for hematopoiesis after 25
Ribs, sternum, vertebrae
Define sinusoids
Unique vascular units that line adventitial cells and allow hematopoietic products to cross in to blood vessels
Define functions of adventitial cells
Produces reticular fibers and secrete cytokines
Define red bone marrow. What are its functions?
Located within medullary cavity of young long bones and spaces of spongy bones
Comprised of mainly developing RBCs and megakaryocytes
Where do erythrocytes and megakaryocytes develop in red bone marrow
Near the sinusoidal wall
Where do granulocytes develop in red bone marrow
In cell nests farther from the sinusoid wall
Define yellow bone marrow. What are its functions?
Contains predominantly adipose tissue
Found in medullary cavity of adult bones and is no longer hematopoietically active
Define yellow bone marrow in hematopoetically active adult bone marrow
50/50 adipose hematopoietic tissue
Can revert to red bone marrow if needed
Equation for normal cellularity
Age - 100 +/- 10%
What does CSF stand for
Colony stimulating factors
What does IL-3 do
Influences replication and growth potential of hematopoetic progenitors
What does IL 2 do
T-cell growth factor
What does IL 1 and 4 do
Acts on pluripotent SCs to develop lymphoid stem cells
What does IL 6 do
B-cell growth factor
Where is EPO produced? What about TPO?
EPO - kidneys
TPO - Liver
What is GM-CSF produced by and what does it do
Produced by endothelial cells, T cells, fibroblasts, and monocytes
Stimulates formation of leukocytes and reticulocytes
What does G-CSF do and what is it produced by
Produced by endothelial cells, fibroblasts, and macrophages
Stimulates an increase in neutrophils
What does M-CSF do
Stimulates an increase in monocytes and macrophages
What granuol precursor produces the first azurophilic granules and where
Promyelocyte in the GA
What granulocyte precursor produces the first specific granules
Myelocyte
Immature neutrophils enter what in bone marrow
Reserve pool
Define a left shift
Bands form, metamyelocytes and myelocytes enter circulation early due to others being drained
T cells develop where and are produced where
Produced in BM, develop in thymus
