Chapter 8- Erythrocyte production and Destruction Flashcards
RBCs are formally called
Erythrocytes
The nucleated precursors in the bone marrow are called
erythroblast/ also called normoblasts
The stage of maturation of any blood cell is determined by careful examination of the
nucleus and the cytoplasm
qualities of greatest importance in identification of RBCs are the
nuclear chromatin pattern (texture, density, homogeneity), nuclear diameter, nucleus: cytoplasm ration, presence or absence of nucleoli, and cytoplasmic color
N:C
nuclear: cytoplasm
N:C
used to identify and stage red blood cell and white blood cell precursors.
the identifiable precursors of mature RBCs, in order from youngest to oldest
Pronormoblast, basophilic normoblast, polychromatic normoblast, orthochromic normoblast, polychromatic erythrocyte or reticulocyte.
days for the BFU-E (burst-forming unit-erythroid) to mature to an RBC
18-21 days
the mature erythrocyte has a life span of
120 days
two (2) functionally identifiable progenitors
BFU-E ( burst-forming units-erythroid)
CFU_E ( colony- forming unit- erythroid)
both committed to to the erythroid cell line.
Function of Erythrocyte
to carry oxygen from the lung to the tissues, where the oxygen is released. accomplished by attachment of oxygen to hemoglobin
process encompassing replication, to increase cell numbers and development from immature to mature cell stages
normoblastic proliferation
the earliest morphologically recognizable erythrocyte precursor
pronormoblasts
single pronormoblast
can usually result to 8-32 mature RBCs
commonly used stain in hematology
romanowsky stain, such as Wright-giemsa
Nucleus (pronormoblast)
Takes up much of the cell (N:C ratio of 8:1)
- round to oval
- containing 1-2 nucleoli
Cytoplasm(pronormoblast)
the cytoplasm is dark blue because of the concentration of ribosomes
Division(pronormoblast)
the pronormoblast undergoes mitosis and gives rise to two daughter pronormoblast.
Location (pronormoblast)
pronormoblast is present only in the bone marrow in healthy states.
Cellular activity (pronormoblast)
pronormoblast begins to accumulate the components necessary for hemoglobin production
length of time in this stage
this stage last slightly more than 24 hours
nucleus (Basophilic)
The chromatin begins to condense, revealing
clumps along the periphery of the nuclear membrane and a
few in the interior
Cytoplasm (Basophilic)
When stained, the cytoplasm may be a deeper,
richer blue than in the pronormoblast—hence the name
basophilic for this stage
Division (Basophilic)
The basophilic normoblast undergoes mitosis, giving rise to two daughter cells.
Location (Basophilic)
The basophilic normoblast is present only in
the bone marrow in healthy states
Cellular Activity (Basophilic)
Detectable hemoglobin synthesis occurs, but the many cytoplasmic organelles, including ribosomes
and a substantial amount of messenger ribonucleic acid (RNA;
chiefly for hemoglobin production), completely mask the
minute amount of hemoglobin pigmentation.
Length of time (Basophilic)
This stage lasts slightly
more than 24 hours