Hematopoesis Flashcards
What are totipotent cells?
cells that give rise to all cells of an organism, including embryonic and extraembryonic tissues; e.g. a zygote.
What are pluripotent cells?
cells that give rise to all cells of the embryo and adult tissues; e.g. embryonic stem cells.
What are multipotent cells?
cells that give rise to different cell types of a given lineage (e.g. adult stem cells).
Where are embryonic stem cells from?
the inner mass of blastocysts; they are pluripotent.
Where do adult stem cells come from?
mature organs/tissues (bone marrow).
Where does hematopoesis occur during the first six months of gestation?
blood islands -> liver -> spleen
What is red marrow the source of?
all blood cells
What are the 4 components of bone marrow?
stroma, parenchyma, sinusoids and hematopoetic cords
What does the stroma do?
synthesizes and secretes hematopoeitic growth factors.
What does the parenchyma do?
contains various lineages of hematopoetic cells in different stages of differetiation.
What do the sinusoids do?
provide access for mature blood cells to move; they are lined by endothelium
What are the hematopoietic cords?
they are bands of parenchyma and stroma lying between the sinusoids.
What are the three major multipotential stem cells?
hematopoietic stem cell (HSC), myeloid stem cell, lymphoid stem cells
What does the HSC differentiate into?
myeloid stem cells and lymphoid stem cells.
How do mature blood cells migrate in the bone marrow?
from the hematopoietic cords through the sinusoidal endothelial walls into the sinusoids.
What is the myeloid/erythroid ratio?
Total volume of cells in granulocytopoiesis/total volume of cells in erythropoiesis.
What cells do lymphocytes produce?
T cells and B cells.
What cells are derived from myeloid stem cells?
granlocyte-macrophages, eosinophil, basophil, magakaryocytes and erythroid cells.
How do mature cells migrate into the blood stream?
they migrate from the hematopoietic cords into the sinusoids.
What molecule is too large to migrate from the hematopoietic cords into the sinusoids?
megakaryocytes.
What are the three compartments of hematopoietic cells?
stem cell, differentiating and functional compartment.
What compartment/niche of the stem cell does the functional compartment contain?
Immediate precursors of mature blood cells, as well as mature blood cells.
True or false: hematopoietic stem cells are pluripotential
True; they can become myeloid or tem cells.
What kinds of cells do myeloid cells give rise to?
all blood cell lines except lymphocytes.
What kind of cells do lymphoid stem cells give rise to?
lymphoid stem cells
What are the two divisions of leukocytes?
granulocytes and agranulocytes. PIC
What leukocytes are classified as granulocytes?
neutrophils, basophils, and eosinophils. PIC
What leukocytes are classified as agranulocytes?
monocytes and lymphocytes. PIC
What is a CFU?
colony forming unit.
The myeloid stem cells give rise to what CFUS?
erythroid, megakaryocyte, basophil, eosinophil and granulocyte macrophage.
When an erythroid interacts with erythropoietin, what molecule is formed?
proerythroblast PIC
When a myegakaryocyte CFU interacts with thrombopoietin, what molecule is formed?
megakaryocytoblast PIC
When a basophil CFU interacts with SFC, what molecule is formed?
myeoblast PIC
When an eosinophil CFU interacts with SFC, what molecule is formed?
myeloblast PIC
When a granulocyte/monocyte macrophage CFU interacts with M-CSF, what molecule is formed?
monoblast PIC
What are the final products of the differentiation of granulocyte macrophage CFUs?
macrophages and neutrophils
What is the final product of the differentiation of erythroid cfus?
eosinophils
What is the final product of the differentiation of basophil CFUs?
mast cells
The lymphoid stem cell gives rise to what cell lines?
T cells and B cells
Where do T-cells mature?
thymus
Where to B-cells mature?
bone marrow
What is the lineage of neutrophils, basophils and eosinophils?
myeloblast -> pro -> myelocyte -> meta -> mega -> band -> final product; each step (except the last) includes a myelocyte. PIC
What is the lineage of marcophages?
monoblsat -> pro -> mono -> macrophage; each step inclues a monoblast. PIC
What is the lineage of megakaryocytes?
megakaryoblast -> megakaryocytes -> platelets
What is the lineage of erythryocytes?
proerythroblast -> basophilic -> polychromatic -> orthochromatic -> reticulocyte -> erythrocyte
Erythroidpoeitin isfound in the liver and is induced by what kind conditions in the body?
hypoxia and heart/lung diseases.
G-CSF is found in endothelial cells It is induced by what response?
inflammatory response.
GM-CSF has what functions?
it supports erythroid cell lineage and stimulates megakaryocyte progenitors.GM
Thrombopoietin is found in the liver induced by what response?
inflammatory response;
Where are hematopoietic growth factors and cytokines produced?
the marrow, fibroblasts and stromal cells.
What are the major groups of hemaopoietic growth factors?
colony stimulating factors, erythropoietin/thrombopoietin and cytokines.
GM-CSF is often used in chemotherapy. What does GM-CSF stimulate?
granulocytopoiesis and monocytopoeisis
What does monocyte colony stimulating factor do?
commits CFU-GM to the monocytic pathway.
When is erythropoietin produced?
When the kidneys have a decreased oxygen saturation. If too much is released, polycythemia can occur.
Where is thrombopoietin produced?
the kidney and liver. It does not have any therapeutic use.
What do cytokines do?
mediates positive and negative effects of apaprotis, proliferation and differentiation; it also starts some signaling pathways.
What do chemoines do?
regulate blood cell trafficking, act as positive/negative feedback regulators.
What are some ECM components of hematopoietic growth factors?
laminin, heparin sulfates, collagen, laminin fibronectin
