Hematopoiesis Flashcards
How many platelets are produced per day?
200 billion
Name the 2 kinds of pluripotential stem cells.
1) CFU-GEMM 2) CFU-L
What does IL-3 do?
promotes production of basophils
What does M-CSF stand for?
Monocyte colony stimulating factor
Name the erythroid precursors in ascending order of maturity.
pronormoblast basophilic normoblast polychromatophilic normoblast orthochromatic normoblast reticulocyte erythrocyte
When the cell undergoes repeated DNA doublings without undergoing cell division, this is called _____.
endoreduplication
Describe a Monocyte.
15-18 micrometer diameter; blue cytoplasm with red-purple granules; no nucleoli
Burst Forming Unit-Erythroid (BFU-E) is the progenitor cell that gives rise to _____.
CFU-E
By the time an individual is 18 to 20 years old, 90% of hematopoietically active marrow is located in the _____, ____, _____, _____, and _____.
vertebrae; pelvis; sternum; ribs; skull
The _____ eventually flows into a central vein and from there into the systemic circulation.
capillary-venous sinus blood
What is the half life, in circulation, of a neutrophil?
7 hours
Stem cells give rise to ______, which in turn give rise to precursor cells.
progenitor cells
_____ are capable of cell division but cannot self-renew.
Precursors
Precursors are capable of ____ but cannot _____.
cell division; self-renew
What does Granulocyte colony stimulating factor (G-CSF) do?
promotes granulopoiesis
What promotes production of eosinophils?
IL-5
Hematopoiesis outside of the bone marrow after birth is abnormal and is called ______.
extramedullary hematopoiesis
How many RBCs are produced every day?
175 billion
What is the average life span of a platelet?
7-10 days
What does Monocyte colony stimulating factor (M-CSF)do?
promotes monopoiesis
What does IL-3 stand for?
Interleukin-3
Describe a platelet.
2 to 4 micro-m in diameter; anucleate; granular and purplish
The capillary-venous sinus blood eventually flows into a central vein and from there into the ______.
systemic circulation
What is self-renewal?
mitosis produces daughter stem cells that are unchanged from the parent as well as cells that can commit to a lineage
What promotes granulopoiesis and monopoiesis?
GM-CSF
Where does hematopoiesis occur in the early embryo?
in the yolk sac
Describe a Monoblast.
16 micro-m in diameter; slightly indented nucleus; very blue cytoplasm; no granules
What is the Myeloid:erythroid ratio (M:E ratio)?
the ratio of granulocytic to erythroid precursors in the bone marrow
Describe a Megakaryoblast.
20 to 30 micro-m in diameter; large round nucleus; small rim of cytoplasm
When does hematopoiesis occur in the yolk sac?
until 3 mos gestation
Describe a Band.
13 micro-m; horseshoe shaped nucleus; almost completely secondary granules
What is the M:E ratio in healthy bone marrow?
3:1
Where are platelets shed from the megakaryocyte to?
directly into the marrow vascular sinuses from the ends of megakaryocyte cytoplasmic arms that extend through the endothelium into the vascular lumens
_____ course into and through the bone marrow and branch into capillaryvenous sinuses.
Nutrient arteries
What does CFU-L stand for?
colony forming unit- lymphoid
Describe a pronormoblast.
18 micro-m in diameter; large nucleus contains finely granular chromatin; one to two fairly inconspicuous nucleoli; cytoplasm contains a lot of RNA so it stains intensely blue
Bone marrow cellularity = ?
100- age
What does CFU-GEMM stand for?
colony forming unit- granulocyte/erythroid/monocyte/megakaryocyte
What does GM-CSF stand for?
Granulocyte-monocyte colony stimulating factor
The erythrocyte cytoplasm progressively accumulates _____ and organelles are progressively lost.
hemoglobin
Describe a Polychromatophilic normoblast.
10-12 micro-m in diameter; hemoglobin starting to accumulate; plentiful RNA imparts a purplish-blue color to the cytoplasm; nucleus smaller; chromatin in chunks
What is EPO?
Erythropoietin; promotes erythropoiesis in response to hypoxia
Describe a Reticulocyte.
anucleate; bluish-purple tinge and is said to be polychromatophilic; ribosomes and mitochondria condense and form strands
What is the Megakaryocyte to platelet scheme?
megakaryoblast to promegakaryocyte to megakaryocyte to platelet
Capillary-venous sinuses are composed of ______, _____, and ______.
an endothelial cell layer, basement membrane, and an adventitial layer
What are the myeloid progenitors?
CFU-GM (Granulocyte/Macrophage); CFU-G (Granulocyte); CFU-M (Monocyte); CFU-E (Erythroid); CFU-Meg (Megakaryocyte); CFU-Eo (Eosinophil); CFU-Baso (Basophil).
Stem cells give rise to progenitor cells, which in turn give rise to _____.
precursor cells
What is a CFU-GEMM?
the mother of all non-lymphoid blood cells
The “______” of the bone marrow means the portion of the marrow that is hematopoietically active.
cellularity
______ give rise to progenitor cells, which in turn give rise to precursor cells.
Stem cells
Describe Erythrocytes.
7 to 8 micro-m in diameter; biconcave; central area of pallor; orange-red in color
When does hematopoiesis occur in the liver and spleen?
in gestational months 3 thru 7
Describe an Orthochromatic normoblast.
8-10 micro-m in diameter; cytoplasm has a distinct red-orange hue; small, shrunken pyknotic nucleus
The cellularity of the bone marrow decreases with ____.
age
Where does hematopoiesis occur from gestational months 3-7?
the liver and spleen
The ______ is used to assess bone marrow iron stores – iron stains blue.
Prussian blue stain
Stromal elements include _____, _____, _____, _____, _____, _____, and ______.
endothelial cells; reticular cells; fibroblasts; lymphocytes; macrophages; adipocytes; and the extracellular matrix
______ results in the formation of a reticulocyte.
Extrusion of the pyknotic nucleus
The erythrocyte cytoplasm progressively accumulates hemoglobin and organelles _____.
are progressively lost
_______ is abnormal and is called extramedullary hematopoiesis.
Hematopoiesis outside of the bone marrow after birth
What causes EPO to be released?
hypoxia
What does IL-5 stand for?
Interleukin-5
Describe a Myeloblast.
15 micro-m across; high nuclear to cytoplasmic ratio; 1 or more nucleoli; blue cytoplasm b/c of RNA but no granules
Describe a Basophilic normoblast.
12 to 14 micro-m in diameter; basophilic cytoplasm; Coarse condensation of the nuclear chromatin has begun
Which cell undergoes endoreduplication?
the megakaryocyte
What is the largest cell in the peripheral blood?
a monocyte
Extrusion of the pyknotic nucleus results in the formation of a ______.
reticulocyte
Precursor cells mature into ______.
the mature cells
What does IL-5 do?
promotes production of eosinophils
What does Granulocyte-monocyte colony stimulating factor do?
promotes granulopoiesis and monopoiesis
_____ is the progenitor cell that gives rise to CFU-E.
Burst Forming Unit-Erythroid (BFU-E)
What promotes megakaryopoiesis?
Thrombopoietin (TPO)
Describe a Promyelocyte.
20 micro-m across; coarse cromatin; large purple granules in blue cytoplasm
What does G-CSF stand for?
Granulocyte colony stimulating factor
Describe a Seg.
same as a band but nucleus has 2-5 lobes (usually 3)
______ mature into the mature cells.
Precursor cells
Name the Granulocytic precursors in ascending order of maturity.
myeloblast promyelocyte myelocyte metamyelocyte band segmented granulocyte (seg)
What is the end result of endoreduplication?
a multilobulated nucleus containing 16, 32 or 64 sets of chromosomes
Describe a promonocyte.
16-18 micro-m in diameter; indented nucleus; 1+ nucleoli; red-purple granules in blue cytoplasm
Describe an Eosinophil.
13 micro-m in diameter; orange-red granules; segmented nucleus is usually bilobed (oval shaped)
multipotential hematopoietic stem cell (HSC)
gives rise to all blood cells- mother of all stem cells- gives rise to lymphoid and myeloid lines
What are HGFs?
hematopoietic growth factors
Describe a Megakaryocyte.
lobulated nucleus; copious cytoplasm that appears finely granular and purplish
______ travel through the blood to the connective tissues of the body where they become macrophages.
Monocytes
What is the average life span of an RBC?
120 days
What promotes production of basophils?
IL-3
What does lymphoid refer to?
T cells, B cells, and NK cells
What is TPO?
Thrombopoietin- promotes megakaryopoiesis
The Prussian blue stain is used to assess iron stores – iron stains _____.
blue
What is endoreduplication?
repeated DNA doublings w/o division
______ include endothelial cells; reticular cells; fibroblasts; lymphocytes; macrophages; adipocytes; and the extracellular matrix.
Stromal elements
Name the monocyte/macrophage lineage scheme.
monoblast to promonocyte to monocyte
Describe a Myelocyte.
15 micro-m across; lavender secondary granules; can still divide
What is a CFU-L?
the mother of all lymphoid cells
By the time an individual is ______, _____ of hematopoietically active marrow is located in the vertebrae, pelvis, sternum, ribs and skull.
18 to 20 years old; 90%
Normally only _____ are allowed to pass from the marrow into the sinuses and subsequently into the peripheral circulation.
mature cells
Normally only mature cells are allowed to pass from the marrow into the _____ and subsequently into the _____.
sinuses; peripheral circulation
How many neutrophils are produced per day?
70 billion
Nutrient arteries course into and through the bone marrow and branch into _____.
capillaryvenous sinuses
______ are composed of an endothelial cell layer, basement membrane, and an adventitial layer.
Capillary-venous sinuses
Monocytes travel through the blood to the connective tissues of the body where they become ______.
macrophages
The “cellularity” of the bone marrow means the portion of the marrow that is ______.
hematopoietically active
Describe a Metamyelocyte.
14-15 micro-m; pinkish-purple cytoplasm bc of all the granules; indented nucleus
Describe a Promegakaryocyte.
lobated nucleus; granules in very blue cytoplasm
Describe a Basophil.
10 micro-m in diameter; lobular but nonsegmented nucleus; blue-purple granules
_____ give rise to the mature, functional cells in the peripheral blood, lymphoid organs, and reticuloendothelial system.
Precursor cells
The capillary-venous sinus blood eventually flows into a _____ and from there into the systemic circulation.
central vein
