Ch. 8 - Erythrocyte Production and Destruction Flashcards
The body’s response to diminished oxygen-carrying capacity of the blood
Anemia
Major cytoplasmic component of mature RBCs for the attachment of oxygen
Hemoglobin
2 functionally identifiable erythroid progenitors
- Burst-forming unit-erythroid (BFU-E)
- Colony-forming unit-erythroid (CFU-E)
3 erythroid precursors
- pronormoblast
- basophilic normoblast
- polychromatophilic normoblast
How many mature RBCs result from a single pronormoblast?
8
Stains used in examining peripheral blood film or bone marrow smear
Modified Romanowsky stain: Wright or Wright-Giemsa
Maturation sequence of RBCs (rubriblastic)
- rubriblast
- prorubricyte
- rubricyte
- metarubricyte
- polychromatophilic erythrocyte
- erythrocyte
3 erythroid precursors capable of mitotic division
- pronormoblast
- basophilic normoblast
- polychromatophilic normoblast
First erythroid precursor without nucleoli
Polychomatophilic normoblast
Small fragments of nucleus that are left behind if the pseudopod-like projection is pinched off before the entire nucleus is enveloped by cell membrane
Howell-Jolly bodies
Erythroid precursor during which the nucleus is ejected
Orthochromic normoblast
2 erythroid maturation stages without nucleus
- Polychromatic erythrocyte
- erythrocyte
Enzyme in polychomatophilic erythrocyte that digests ribosomes
Endoribonuclease
Residual ribosomes in polychromatophilic erythrocytes that appear as a mesh of small blue strands or blue dots
Reticulum
Stained polychromatophilic erythrocytes with reticulum
Reticulocytes
2 characteristics of the membrane of the erythrocyte responsible for oxygen delivery
- flexible
- deformable
Dynamics of RBC production and destruction
Erythrokinetics
Collection of all stages of erythrocytes throught the body
Erythron
Term that refers only to the cells in circulation
RBC mass
Location of the primary oxygen-sensing system of the body. Detects hypoxia
Peritubular interstitial cells of the kidney
Condition where there is too little oxygen
Hypoxia
Produces erythropoietin
Peritubular cells of the kidney
Major stimulatory cytokine for RBCs
Erythropoietin (EPO)
The mechanism by which hypoxia increases EPO production in peritubular cells
Transcriptional regulation
Component of erythropoietin that reacts specifically with RBC receptors
Carbohydrate unit
Component of erythropoietin that is necessary for biologic activity in vivo
Terminal sialic acid unit
Mediates EPO’s effects that in turn affect gene activities in the RBC nucleus
Intracellular Janus tyrosine kinase signal transducers
Death receptor on the earliest RBC precursors whic is expressed by more mature RBCs
Fas and its ligand, FasL
A mechanism to escape apoptosis where there is stimulation of antiapoptotic molecules which allows the cell to survive and mature
EPO rescue
Cell that has the most EPO receptors and is most sensitive to EPO
CFU-E
The antiapoptotic molecule that results from the cooperation of EPO and the transcription factor GATA-1
bcl-xL
Substance that is synthesized due to EPO which effectively increases the rate of many processes, especially hemoglobin production
RBC RNA
Cells that exit the marrow during conditions boen marrow stress, such as anemias.
Large, bluish cells lacking central pallor
Stress reticulocytes
Place where hematopoiesis occurs. A loose arrangement of cells in a dilated sinus area between the arterioles that feed the bone and the venous sinus that returns the blood to efferent veins
Marrow cords
Place where erythropoiesis occurs. Macrophages surrounded by erythroid precursors in various stages of development.
Erythroid islands
Secreted by macrophages during erythropoiesis
Ferritin
Substance where developing RBCs obtain the most iron
Transferrin
3 components of the anchoring system during erythropoiesis
- stable matrix of stromal cells to which normoblasts can attach
- bridging (adhesive) molecules for attachment
- receptors on the erythrocyte membrane
Anchors the RBCs to the extracellular matrix to the bone marrow
Fibronectin
Cellular aging
Senescence
2 plasma proteins that salvage the released hemoglobin during intravascular hemolysis so that its iron is not lost
- haptoglobin
- hemopexin