Histology Blood 2 11.15.12 Flashcards
What is extrameduallry hematopoieses
In times of severe blood loss when liver and slpeen carry out hematopoieese
What is Hematopoieis? Where does it begin as embryo? as adult? in severe blood loss?
process by which new mature blood cells are generated from precursors.
Embryonic life in YOLK SAC, LIVER, SPLEEN, BM
Adulthood- in BM. If severe blood loss, liver and spleen an carry out hematopoieses
Red marrow vs Yellow marrow.
Red-
high nuber of erythroid (red) cells
active in hematopoieses
the only type of marrow fournd in human bones until adolescence
Yellow marrow
inactive in hematopoieis
high fat (yellow) content
Demand for renewal of RBC population (anemia , illness, hemorrhage, conversts yellow marrow back to red marrow and resutls in inc in hemato
What two series does the comon ancestral cell (totipotential hetopoietic stem cells or CFU) give rise to?
Myeloid or Lymphoid
What are the Myeloid originated cells? (5)
Erythorcytes (RBC) Granulocytes Mnocytes Megakaryocytes Mast Cells
What are from Lymphoid origin?
T and B lymphocytes
What are teh two compartments prsent in BM?
Hematopoietic compartment-
and vascular compartment
What is in the Hematopoietic compartment?
iwll reticular (sromal) cells, fat deposits, and reticular fibers that support hematopoietic cords (grous of newly-forming blood cells, with ceach clump of cells being daughter cells iwth common ancestory)
What is the the Vascular Compartment of BM
contains branches of large nutrient arteries that peirce cortical bone, giving out small arteries to bone Haverisan systems before enteing marrow cavity
Endothelial cells have MIGEATION PORES thorugh which newly formed mature blood cells int he marrow cavity undergo DIAPEDSIS, which si a revptor mediated crossing of the endotheliu and enthering peripheral ciruclation
What is in the BM spread?
mostly RBC (periphery)
What is the order of RBC development?
PBPORE
(Hemocytoblaast) (Erythroblast stem cell) Proerythroblst Basophilic Erythroblast Polychromatic Erythroblast Orthochromatic Erythroblast (Normoblast) Reticulocyte Erythrocytes
HEmoglobin and RNA relation during RBC maturation
RNA decreases while Hb increses as cells mature
what is Basophilic erythroblast?
cell is ame size or smaller than hemocytoblast and is the most basophilic marrow cell
Polychromatophilic Erythroblst
characteristic “Checkerboard” arrangmented of clumped chromatin in its nucleus
cytoplasm has gray color
Orthocrhromatic eyrthoblast (normoblast)
highly condensed nucleus
acidophlic staining refelcts incresed amt of Hb in teh cytoplasm
Cytopslam is similar in color to mature RBCs
First stem cell incapable ofmitosis
Nucleus is ejeted durign thsi stage
Reticulocyte
has small residual ribosomal RNA.
Slighlty larger than RBCs, retics can only be idenfieifed with a special stain (stains blue)
about 2% of circulating RBCs are reticulocytes. Sudden demand fro ne RBCs, in hemorrhage for example ,will lead to an incrase in teh number of retics in peripheral blood
What are the two important functions in STem Cells
- REPRODUCTION - to maintain their small, constant population
- DIFFERENTATION- to give rise to two lines of committed daughter cells
- a) colony forming units (CFU) of granulytes, RBC, monocytes and megakaryocytes
b) lymphoid stem cells
Hematopoietic Compartment
contains reticular (stromal) cells, fat deposits, and reticular fibers that serve as a supprot for HEMATOPOEITIC CORDS (groups of newly-forming blood cells , with each clump of cells being daugher cell witha common ancestry
What is the first RBC maturing cell that is incapable of mitosis>
Orthochromatophilic erythroblast (normoblast); during this stage, nuclues is ejected
What is blood and where is it dervied?
It is a specialized CT and therefore, ultimately derived from MESENCHYAL TISSUE
Where si the BM usually located
primarily in the large spacaes within long bones
Marrow-rich areas are the PUBIC bone, Sternum, FEMUR< and TIBIA
What part of erythropoiesies responds to erythropoieitin
Intermediate Erythroid Stem Cellqwha
what is the first cell in RBC development that is incapapble of mitosis
Orthocromatophillic Erythroblast
What organ releases Erythropoietin
Rleased by the O2 sensor, KIDNEY
