Hematopoiesis Flashcards
Myeloid cells capable of transporting O2
Erythrocytes
Functions of blood
Regulation of pH, osmosis
Maintenance of body temperature
Protection against foreign substances
Clot formation
4 types of myeloid cells
Erythrocytes
Granulocytes
Monocytes
Megakaryocytes
Precursor of lynphocytes
Lymphoid stem cells
Production and development of formed elements
Hematopoiesis
Pleuripotent vs progenitor cells
Pleuripotent - able to differentiate into any type of cell
Progenitor - decided on fate; precursor to a differentiated cell of the same tissue type
Types of membranous bones
Ribs, sternum, vertebrae
– active in adult hematopoiesis
Three phases of hematopoiesis
Mesoblastic, Hepatic, Medullary
Stage of hematopoiesis wherein undifferentiated mesenchymal cells differentiate to clustered hemangioblasts, which further differentiate into endothelial and primitive blood cells
Mesoblastic (yolk sac)
Hematopoeitic phase wherein liver bone marrow is the primary site of blood production
Medullary phase
Alternative sites for producing blood cells in the adult
Thymus, lymph nodes, spleen
Filters blood, gathers, transfers, and eliminates waste substances via bile acids
Liver
Functions to remove damaged RBCs, synthesize immunoglobulin M, and store 30% of platelets
Spleen
Disease related to enlargement of the spleen
Thalassemia
Origin of the thymus
Yolk sac, liver
Site where B and T lymphocytes go to finish maturation
Lymph nodes
Function of bone marrow stromal cells
Regulate cytokine activity (nonstromal cells synthesize cytokines)
Molecule class which includes interleukins, growth factors, interferons
Cytokines
Critical cytokines in hematopoiesis
IL-3, stem cell factors, erythropoietin
Molecule that stimulates development of red blood cells
Erythropoietin
Average life span of RBC
120 days
In succeeding generations of erythropoiesis, ____ increases whereas the ________ is diminished
Hemoglobin, basophilic nucleus
T/F: increasing hematocrit will signal the liver and kidneys to stop producing erythropoietin.
T – feedback inhibition of erythropoiesis by RBC concentration
Hematopoietic cytokine able to regulate cell functions including differentiation of macrophages and granulocytes, dendritic cell development, homeostasis
GM-CSF (granulocyte-macrophage colony stimulating factor)
Promotes the early proliferation of primitive cells
SCF (stem cell factor)
Molecules important for RBC synthesis (cofactors)
Iron, vitamin b12, folic acid
Formation and development of white blood cells
Leukopoiesis
Ability of white blood cells to transport themselves via amoeboid motion in between nonvascular tissues
Diapedesis
How do leukocytes know where to travel?
Chemotaxis
Granulocyte with multilobed nucleus; phagocytoses bacteria and fungi
Neutrophils
Granulocyte with bi-lobed nucleus; active during helminthic infections and inflammation
Eosinophils
Granular leukocyte with lobed nucleus; causes vasodilation by the release of histamines
Basophils
General term for basophils, neutrophils, and eosinophils
Polymorphonuclear leukocytes / granulocytes
Precursors of mature granulocytes
Myeloid precursors
Most immature form of granulocytes with an undifferentiated, round-ovoid nucleus devoid of granules
Myeloblast
Granules which develop in promyelocytes
Azurophilic granules
White blood cell with prominent secondary granules, kidney shaped nucleus
Metamyelocyte
Second most common leukocyte in adults
Lymphocytes (these however, are the most abundant in children. Neutrophils are the most abundant in adults)
Precursor cell which gives rise to macrophages, provides defense against viruses and intracellular bacteria in chronic infections
Monocyte
Site of maturation for B lymphocytes
Periphery lymphoid organs (lymph nodes, spleen)
Common lymphoid progenitor
Bone marrow
CD4 vs CD8 t-cells
CD4: helper T cells
CD8: cytotoxic T cells
Megakaryopoiesis regulator
Thrombopoietin
Three stages of megakaryopoiesis
Basophilic, granular, mature
T/F: basophilic megakaryocytes display polyploidy.
False. Granular megakaryocytes are more polyploid due to repetitive DNA replication
Disease characterised by reduced oxygen carrying capacity of the blood
Anemia
Interpret leukocyte shift to the left vs leukocyte shift to the right
Shift to the left: presence of more immature leukocyte forms (probably due to infection or leukemia)
Shift to the right: presence of more mature leukocytes (may be due to megaloblastic anemia)
Presence of abnormally increased nuclear lobulation, seen in megaloblastic anemia
Hypersegmentation
Excessive leukocytic response; overproduction of leukocytes
Leukomoid reaction
Other term for progenitor cells
Colony-forming units
Theory in which each of the blood cell lineages is derived from its own unique stem cell
Polyphyletic theory
All blood cells arise from a single pleuripotent stem cell
Monophyletic or unitarian theory
Significance of B12 in erythropoiesis
Synthesis of thymidine triphosphate
(Rough/smooth) surfaces tend to enhance phagocytosis
Rough
Phenomenon wherein antibodies adhere to foreign membranes, tagging them for macrophage selection and phagocytosis
Opsonization
