ERYTHROPOIESIS PPT Flashcards
Erythrocyte has one true function:
to carry oxygen from the lung to the tissues, where the oxygen is released.
RBCs are formally called
erythrocytes
nucleated RBC precursors, normally restricted to the bone marrow
Erythroblasts/ normoblasts
Morphologic identification of blood cells depends on a ________
well-stained peripheral blood film or bone marrow smear
Commonly used stain/s, in identification of erythroid precursors.
Modified Romanowsky stain (Wright or Wright- Giemsa)
The stage of maturation of any blood cell is determined by careful examination of the:
nucleus and the cytoplasm.
The most important features in the
identification of RBCs are the:
-Nuclear chromatin pattern (texture, density, homogeneity),
- Nuclear diameter
-Nucleus-to-cytoplasm (N:C) ratio
-Presence or absence of nucleoli,
-Cytoplasmic color
The nucleus is round to oval, containing
one or two nucleoli. The purple red chromatin is open and contains few, if any, fine clumps.
Pronormoblast (Rubriblast)
The nucleus takes up much of the cell (N:C
ratio of 8:1) in ______
Pronormoblast (Rubriblast)
The cytoplasm in Pronormoblast (Rubriblast) is dark blue because of the concentration of?
ribosomes and RNA along the periphery.
The pronormoblast undergoes mitosis and gives rise to ?
two daughter pronormoblasts
More than one division is possible before maturation into basophilic normoblasts.
Pronormoblast (Rubriblast) Division.
Location of Pronormoblast
Bone marrow
The pronormoblast begins to accumulate the components necessary for ______ production.
hemoglobin production
In pronormoblast the_________ necessary for iron uptake and protoporphyrin synthesis are produced.
proteins and enzymes
Globin production begins.
Pronormoblast (Rubriblast) celluar activity
Length of time in Pronormoblast stage.
lasts slightly more than 24 hours.
The chromatin begins to condense, revealing clumps along the periphery of the nuclear membrane and a few in the interior.
Nucleus of Basophilic Normoblast (Prorubricyte)
Basophilic Normoblast (Prorubricyte)
Cytoplasm. When stained, the cytoplasm color may be ________than in the pronormoblast, hence the name basophilic for this stage.
deeper, richer blue
N:c ratio decreases to about 6:1
Basophilic Normoblast (Prorubricyte)
Basophilic Normoblast (Prorubricyte)
Division. The basophilic normoblast undergoes mitosis, giving rise to?
two daughter cells
Basophilic Normoblast (Prorubricyte) location?
Bone marrow
Basophilic Normoblast (Prorubricyte)
Cellular activity?
Detectable hemoglobin synthesis
Basophilic Normoblast (Prorubricyte). Length of time in this stage.
lasts slightly more than 24 hours.
The chromatin pattern varies during this stage of development, showing some openness early in the stage but becoming condensed by the end.
Polychromatic (Polychromatophilic) Normoblast (Rubricyte) Nucleus.
the condensation of chromatin reduces the diameter of the nucleus , N:C ratio decreases from 4:1 to?
1:1 by the end of the stage
no nucleoli are present.
Polychromatic (Polychromatophilic) Normoblast (Rubricyte) Nucleus.
no nucleoli are present.
Polychromatic (Polychromatophilic)
Normoblast Cytoplasm. The color produced is a mixture of pink and
blue, resulting in
murky gray-blue
Polychromatic normoblast stage refers to the combination of multiple colors or “many colors” referred as:
polychromatophilic
This is the last stage in which the cell is capable of undergoing mitosis.
Polychromatic (Polychromatophilic)
Normoblast (Rubricyte)
Cellular activity. Hemoglobin synthesis increases, and the accumulation begins to be visible as a pinkish color in the
cytoplasm.
Polychromatic (Polychromatophilic)
Normoblast (Rubricyte)
Length of time in Polychromatic (Polychromatophilic) Normoblast (Rubricyte)
stage lasts approximately 30 hours.
The nucleus is completely condensed (i.e.,
pyknotic) or nearly so.
Orthochromic Normoblast (Metarubricyte)
Orthochromic Normoblast (Metarubricyte)
Cellular activity. Hemoglobin production continues on the remaining ribosomes using messenger RNA produced earlier. Late in this stage, the_____ ejected from the cell
nucleus
Orthochromic Normoblast (Metarubricyte) Length of time in this stage.
lasts approximately 48 hours.
Beginning at the polychromatic erythrocyte or reticulocytes stage, there is
no nucleus
Can be compared with that of the late orthochromic normoblast in that the predominant color is that of hemoglobin yet with a______due to some residual ribosomes and RNA.
bluish tinge
Lacking a nucleus, the polychromatic erythrocyte or reticulocytes
cannot divide
The polychromatic erythrocyte or reticulocytes resides in the?
bone marrow for about 1 to 2 days
polychromatic erythrocyte or reticulocytes then moves into the_____ for about 1 day before reaching maturity.
peripheral blood
The _______completes
production of hemoglobin from a small amount of residual messenger RNA using the remaining ribosomes.
polychromatic erythrocyte or reticulocytes
Polychromatic (Polychromatophilic)
Erythrocyte or Reticulocyte Length of time
remains a polychromatic erythrocyte for about 3 days
Polychromatic (Polychromatophilic)
Erythrocyte or Reticulocyte with the first 2
days spent in the___
bone marrow
Polychromatic (Polychromatophilic)
Erythrocyte or Reticulocyte, the third day spent in the____ although possibly sequestered in the
spleen.
peripheral blood,
No nucleus is present in mature RBCs.
Erythrocyte
The mature circulating erythrocyte is a
biconcave disc measuring 7 to 8 mm in diameter.
Erythrocyte
Erythrocytes on a Wright-stained blood film, it appears as _______stained cell with a central pale area that corresponds to the concavity.
salmon-pink
The _____ is about one-third the
diameter of the ERYTHROCYTE cell.
central pallor
The ______ cannot divide.
erythrocyte
Mature RBCs remain active in the circulation for
approximately 120 days.
leads to their removal by the spleen as described subsequently.
Aging Erythrocytes
Orthochromic Normoblast (Metarubricyte) cytplasm . The increase in the _____________ color of the cytoplasm reflects nearly complete hemoglobin
production.
salmon pink
The orthochromic normoblast is present only in the ______ in healthy states.
bone marrow
