Hematopoiesis

Question 1

which is more abundant in the bone marrow - granulocytes or RBCs? why?

Answer 1

granulocytes - much shorter life span

Question 2

what is the role of the bone marrow stromal cell?

Answer 2

maintenance and differentiation of HSCs

Question 3

what is the relationship between stromal cells and HSCs as the HSCs develop?

Answer 3

the more mature a HSC gets, the less firmly it binds to the stromal cells

Question 4

which molecules are responsible for driving cell differentiation pathways?

Answer 4

cytokines

Question 5

GCSF is released by what cell type?

Answer 5

macrophage

Question 6

where is GCSF released?

Answer 6

site of inflammation

Question 7

what does GCSF do once released at a site of inflammation?

Answer 7

circulates to bone marrow so stimulate production / release of neutrophils

Question 8

EPO is produced / released by what cell type?

Answer 8

peritubular interstitial cells of kidney

Question 9

EPO is produced in response to what condition?

Answer 9

hypoxia

Question 10

what does EPO do once released by the kidney?

Answer 10

circulates to bone marrow to stimulate production and release of RBCs

Question 11

what is the role of TGFB on the bone marrow?

Answer 11

decreases cell surface receptors for growth / differentiation cytokines

Question 12

what is the clinical utility of GCSF?

Answer 12

1. BMT - mobilizing stem cells to blood for IV draw

2. stimulates granulopoiesis following chemotherapy induced marrow suppression

Question 13

what is the clinical utility of granulocyte monocyte colony stimulating factor (GMCSF)?

Answer 13

1. increases myeloid cell recovery in bone marrow transplantation patients
2. more toxic than GCSF

Question 14

what is the clinical utility of EPO?

Answer 14

increases RBC mass in renal insufficiency-induced anemia

Question 15

extramedullary hematopoiesis takes place in which organs?

Answer 15

spleen and liver

Question 16

what are the maturational characteristics of erythropoiesis as a cell matures?

Answer 16

1. cell size decreases
2. nucleus:cytoplasm ratio decreases
3. nucleoli decrease in number and eventually disappear
4. lighter blue (less RNA)

Question 17

what must occur before a metarubricyte becomes a reticulocyte?

Answer 17

nucleus extrusion

Question 18

what is the normal “home” for neutrophils?

Answer 18

peripheral blood

Question 19

where do B and NK cells differentiate?

Answer 19

entirely in bone marrow

Question 20

fully mature B cells have which immunoglobulin markers?

Answer 20

IgM and IgD

Question 21

what is the T cell maturation sequence?

Answer 21

1. bone marrow - prothymocytes

2. thymus - maturation / differentiation into T lymphocyte subsets

Question 22

where do T cells go once they leave the thymus?

Answer 22

populate lymphatic organs

Question 23

what is endomitosis?

Answer 23

nuclear mitosis without the cytoplasmic divisions

Question 24

thrombopoiesis is stimulated by what?

Answer 24

thrombopoietin

Question 25

what is the “absolute count”?

Answer 25

provides QUANTITY of each cell type per unit volume

Question 26

what is the “differential count”?

Answer 26

provides RELATIVE count (%) of each cell type

Question 27

what is the normal reticulocyte count?

Answer 27

1%