Term
| The process in which blood cells are continuously replaced with new cells from precursor cells. |
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Definition
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Term
| Blood cells form from stem cells in the __________. |
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Definition
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Term
| Stem cells are pluripotent, which means they are |
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Definition
capable of asymmetric division and self-renewal, some daughter cells form specific, irreversibly differentiated cells,
remain as a small pool of slowly dividing stem cells |
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Term
Hemopoietic stem cells may be isolated using
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Definition
· fluorescence-labeled antibodies and a fluorescence-activated cell-sorting (FACS) instrument. |
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Term
| Pluripotent stem cells proliferate and form two major lineages of progenitor cells called... |
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Definition
| Lymphoid cells-Lymphocytes, and Myeloid cells-granulocytes, monocytes, erythrocytes, and megakaryocytes |
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Term
| Progenitor cells are also called |
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Definition
| colony-forming units, and give rise to ONE cell type. |
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Term
| What are the four major types (lineages) of CFU's? |
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Definition
| Erythroid-Erythrocytes, Thrombocytic-Megakaryocytes, Granulocyte/monocyte-granulocytes and monocytes, Lymphoid-lymphocytes |
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Term
| What do hemopoietic growth factors do? |
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Definition
Also called (colony-stimulating factors or cytokines) are Glycoproteins, Stimulate proliferation of progenitor and precursor cells, Promote cell differentiation and maturation within specific lineages
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Term
| What are the two types of bone marrow? |
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Definition
| Red bone marrow, Yellow bone marrow |
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Term
What are the distinctions of Red bone marrow and Yellow bone marrow?
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Definition
Red-color is produced by an abundance of blood and hemopoietic cells, in newborns all bone marrow is red
Yellow-
filled with adipocytes that exclude most hemopoietic cells under certain conditions may revert back to red
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Term
| What does red bone marrow contain? |
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Definition
a reticular connective tissue stroma (specialized fibroblastic cells),
hemopoietic cords or islands of cells,
sinusoidal capillaries
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Term
| Erythrocyte maturation (a type of terminal differentiation) involves |
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Definition
o hemoglobin syntheses
o formation of a small, enucleated, biconcave corpuscle |
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Term
| What major changes are occurring in erythopoiesis and how long does maturation take? |
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Definition
Cell and nuclear volumes decrease
Chromatin density increases until the nucleus presents a pyknotic appearance and is extruded from the cell.
Gradual decrease in the number of polyribosomes (basophilia)
Increase in amount of hemoglobin (eosinophilic protein)
Mitochondria and other organelles disappear gradually
TAKES APPROX 1 WEEK |
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Term
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Definition
o glycoprotein growth factor
o Stimulates the production of mRNA for globins |
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Term
| What are the cell names as differentiation occurs from a progenitor cell to erythrocyte? |
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Definition
| Progenitor cell to proerythroblast to basophilic erythroblast to polychromatophilic erythroblast to orthochromatophilic erythroblast (also called normablast, stained with a brilliant cresyl blue) to reticulocyte to mature erythrocyte. |
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Term
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Definition
| cytoplasmic changes dominated by synthesis of proteins for the azurophilic granules (Made initially) and specific granules, are produced which differ between the different granulocytes. |
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Term
| Granulocytes are initially |
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Definition
| Myeloblasts- the most immature recognizable cell in the myeloid series |
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Term
| What is the second stage of granulopoiesis? The third? |
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Definition
| Promyelocyte/metamyelocyte |
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Term
| When does the first visible cell differentiation occur in granulopoiesis? |
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Definition
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Term
| What is the distinctive characterisitic of the metamyelocyte stage? |
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Definition
· the cytoplasm is full of the specific granules. |
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Term
| How long does granulopoiesis take? |
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Definition
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Term
| What four compartments/populations exist for developing and mature neutrophils? |
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Definition
o the granulopoietic compartment in the bone marrow
o storage as mature cells in marrow until release
o circulating population
o a population undergoing margination
o A fifth compartment exists where injury or inflammation occurs. |
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Term
| What occurs for maturation of Agranulocytes (monocytes) |
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Definition
(MONOCYTES) Monoblast is the committed progenitor cell
Differentiation leads to promonocyte
Promonocytes divide twice as they develop into monocytes
Differentiating monocytes contain extensive RER and large Golgi complexes forming lysosomes
Circulate in blood until mature into macrophages or other phagocytic cells. |
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Term
| What occurs for maturation of Agranulocytes (lymphocytes) |
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Definition
LYMPHOCYTES- The progenitor of lymphoid cells is the lymphoblast
Lymphoblasts divide two or three times to form lymphocytes
Lymphocytes either migrate to the thymus to become T lymphocytes or stay in the bone marrow to become B lymphocytes prior to migrating to peripheral lymphoid organs. |
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Term
| Explain the origin of Platelets |
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Definition
Originate in the bone marrow by dissociating from mature megakaryocytes, Megakaryoblast TO megakaryocytes, megakaryocytes extend several long, wide branching processes, The cellular extensions penetrate the sinusoidal endothelium and are exposed to the circulating blood
A loop of microtubules forms a teardrop-shaped enlargement , The loops pinch off to form platelets, Each megakaryocyte produces a few thousand platelets before apoptosis and removal by macrophages.
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Term
| What hormone drives megakaryoblasts? |
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Definition
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