Hemopoiesis Quiz.text - - 6/8/99

QUESTION 1:  What is hemopoiesis? ANSWER:  Hemopoiesis is the pathway of the production
of blood cells from stem cells that are present in the bone marrow.

QUESTION 2:  What is erythropoietin? ANSWER:  Erythropoietin is a glycoprotein of
molecular weight approximately 52,000.  It is produced by the kidney and is involved in
the regulation of synthesis of erythrocytes.


QUESTION 3:  What part of hemopoiesis does erythropoietin regulate? ANSWER: 
Erythropoietin regulates the formation of red blood cells ‹ erythropoiesis.  It
specifically regulates the formation of red blood cells from erythrocyte colony forming
cells ‹ CFC-E.

QUESTION 4:  What is the role interleukin-3 (IL-3) in erythropoiesis? ANSWER: 
Interleukin-3 regulates the differentiation of blood stem cells to erythrocyte colony
forming cells ‹ CFC-E.

QUESTION 5:  What role do colony stimulating factors (CFSs) play in the formation of
granulocytes (neutrophils) and macrophages? ANSWER:  Colony stimulating factors are
responsible for the regulation of the differentiation of stem cells to colony forming
cells-granulocyte/macrophage and colony forming cells-granulocyte/macrophage to either
fully differentiated granulocytes or macrophages.

QUESTION 6:  Other than interleukin-3 (Il-3) and colony stimulating factors (CFSs) what
other factors are involved in the development of granulocytes and macrophages? ANSWER: 
Interactions with the ligand Steel  which is usually cell bound and is associated with
cells present in bone marrow.

QUESTION 7:  What are the specific roles that colony stimulating factors (CFSs) can
play in the regulation of hemopoiesis? ANSWER:  Colony stimulating factors (CFSs) can
alter the frequency of cell division, probability of cell death, probability that
daughter cell can become a committed progenitor cell.

QUESTION 8:  What would be the expected outcome on blood cell formation of exposure of
the human body to high levels of g-radiation? ANSWER: The irradiation would effectively
kill blood stem cells and this would result in the decrease of levels of all cells in
the blood.

QUESTION 9:  What cytokines are involved in the regulation of the activation of
T-helper cells? ANSWER:  Interleukin-1 which originates from antibody presenting cells.

QUESTION 10:  What cytokines are involved in the regulation of the proliferation of
T-helper cells? ANSWER:  Interleukin-2 which originates from the activated T-helper
cells.

QUESTION 11:  What receptors and cytokines are involved in the activation of specific
antibody producing B-cells? ANSWER: Interleukins-4 and -5 which originate from
activated T-helper cells, the ligand CD 40 on the activated T-helper cell binding to
its receptor on the B-cell and the antigen present on the surface of the T-helper cell
binding to a specific receptor on the B-cell.

QUESTION 12:  What cytokines are involved in the regulation of the division of
T-cytoxic cells? ANSWER:  Interleukin-2 and interferon which are derived from a
subgroup of T-helper cells TH1 cells.