Erythrocyte Maturation Stages

size: 12-19 um

rubriblast / pronormoblast / proerythroblast size

nucleus: round or slightly oval, thin nuclear membrane, central or slightly eccentric

rubriblast / pronormoblast / proerythroblast nucleus

nucleoli: 1-2

rubriblast / pronormoblast / proerythroblast nucleoli

cytoplasm: small in amount, dark blue (because of concentration of ribosomes), homogenous

rubriblast / pronormoblast / proerythroblast cytoplasm

N:C ratio = 4:1

rubriblast / pronormoblast / proerythroblast N:C ratio

2

rubriblast / pronormoblast / proerythroblast gives rise to ___ rubricytes

rubriblast / pronormoblast / proerythroblast

earliest recognizable erythroid precursor using light microscope

size: 12-17 um

prorubricyte / basophilic normoblast / basophilic erythroblast size

nucleus: round, thin nuclear membrane, smaller, slightly eccentric

prorubricyte / basophilic normoblast / basophilic erythroblast nucleus

nucleoli: 0-1

prorubricyte / basophilic normoblast / basophilic erythroblast nucleus

cytoplasm: deeper, richer blue, more abundant (bc smaller nucleus)

prorubricyte / basophilic normoblast / basophilic erythroblast cytoplasm

N:C ratio = 4:1

prorubricyte / basophilic normoblast / basophilic erythroblast N:C ratio

4

prorubricyte / basophilic normoblast / basophilic erythroblast gives rise to ___ rubricytes

prorubricyte / basophilic normoblast / basophilic erythroblast

last stage w/ nucleolus

prorubricyte / basophilic normoblast / basophilic erythroblast

first stage of hemoglobin synthesis → eosinophilic material

• coarser chromatin

• absence of nucleoli

most helpful criteria in distinguishing the prorubricyte form rubriblast

size: 11-15 um

rubricyte / polychromatic normoblast / polychromatic erythroblast size

nucleus: round, smaller, thick nuclear membrane, eccentric nucleus

rubricyte / polychromatic normoblast / polychromatic erythroblast nucleus

rubricyte / polychromatic normoblast / polychromatic erythroblast

nucleolus starts to disappear from

cytoplasm: gray

rubricyte / polychromatic normoblast / polychromatic erythroblast cytoplasm

more blue + pink Hgb

why does rubricyte / polychromatic normoblast / polychromatic erythroblast cytoplasm appear gray?

N:C ratio = 1:1

rubricyte / polychromatic normoblast / polychromatic erythroblast N:C ratio

2

each rubricyte gives rise to ___ metarubricytes

rubricyte / polychromatic normoblast / polychromatic erythroblast

last stage capable of mitosis

rubricyte / polychromatic normoblast / polychromatic erythroblast

1st stage that the cytoplasm → pink (Hgb pinkness appears)

size: 8-12 um

metarubricyte / ortochromatic normoblast / ortochromatic erythroblast size

nucleus: pyknotic (dense mass of degenerated chromatin)

metarubricyte / ortochromatic normoblast / ortochromatic erythroblast nucleus

cytoplasm: salmon-pink

metarubricyte / ortochromatic normoblast / ortochromatic erythroblast

N:C ratio = 1:2

metarubricyte / ortochromatic normoblast / ortochromatic erythroblast N:C ratio

metarubricyte / ortochromatic normoblast / ortochromatic erythroblast

nucleus extruded, cell becomes reticulocyte

nucleated RBC, pyknotic erythroblast, acidophilic normoblast

metarubricyte / ortochromatic normoblast / ortochromatic erythroblast other names

metarubricyte / ortochromatic normoblast / ortochromatic erythroblast

last stage w/ a nucleus

size: 7-10 um

reticulocyte / polychromatic erythrocyte / diffusely basophilic erythrocyte size

cytoplasm: salmon pink, predominant color — hemoglobin but w/ bluish tinge (some residual ribosomes and RNA)

reticulocyte / polychromatic erythrocyte / diffusely basophilic erythrocyte cytoplasm

reticulocyte / polychromatic erythrocyte / diffusely basophilic erythrocyte

last RBC precursor / last immature stage

reticulocyte / polychromatic erythrocyte / diffusely basophilic erythrocyte

last stage of Hgb synthesis

reticulocyte / polychromatic erythrocyte / diffusely basophilic erythrocyte

young RBCs containing residual RNA

• BM: 2-3 days

• PB: 1 day

reticulocytes spe

“irregular”

shape of reticulocyte is described as ___ in electron micrographs

size: 6-8 um

mature erythrocyte size

cytoplasm: salmon pink (w/ central pallor — 1/3 of cell’s diameter)

biconcave disk

mature erythrocyte shape

1.5-2.5 um

mature erythrocyte thickness

8-32

number of erythrocytes produced from each rubriblast

no mitochondria

adult RBC contains no ___ because there is no protein or Hgb synthesis