Pronormoblast Flashcards

Pronormoblast (Rubriblast)

• Large nucleus occupies significant cell volume with a nuclear-to-cytoplasmic (N:C) ratio of 8:1.
• Nucleus is round to oval, containing one or two nucleoli and purple-red chromatin that is mostly open.

Cytoplasm Characteristics of Pronormoblast

• Dark blue cytoplasm due to high ribosome concentration.
• Potential visibility of the Golgi complex as a pale, unstained area adjacent to the nucleus.
• May exhibit small tufts of irregular cytoplasm along the membrane perimeter.

Cellular Activity of Pronormoblast

• Initiates globin production as part of the cellular activity.

Duration of Pronormoblast Stage

• Life span of the rubriblast is slightly greater than 24 hours.

Basophilic Normoblast (Prorubricyte)

• Chromatin begins to condense, forming clumps on the nuclear membrane and some in the interior.
• N:C ratio decreases to less than 6:1 with chromatin staining deep purple-red; nucleoli may still be present.

Cytoplasm Characteristics of Prorubricyte

• Cytoplasm appears darker, richer blue when stained compared to the pronormoblast.

Polychromatic Normoblast (Rubricyte)

• Chromatin shows variation, remaining open early in the stage but becomes condensed by the end.
• N:C ratio is approximately 4:1, with a significant reduction in nuclear diameter due to chromatin condensation.

Cytoplasm Characteristics of Rubricyte

• First stage where pink color associated with stained hemoglobin becomes visible.
• Cytoplasmic color is a murky gray-blue due to a mixture of pink and blue, indicating reduced RNA.

Cellular Activity of Rubricyte

• Increased hemoglobin synthesis occurs over approximately 30 hours.

Orthochromic Normoblast (Metarubricyte)

• Chromatin is completely condensed at this stage.

Cytoplasm Characteristics of Metarubricyte

• Notable increase in salmon-pink coloration, reflecting nearly complete hemoglobin production.

Duration of Metarubricyte Stage

• This stage lasts about 48 hours.

Polychromatic Erythrocyte (Reticulocyte)

• Characterized by the absence of a nucleus.

Cytoplasm Characteristics of Reticulocyte

• Salmọn-pink in coloration, indicative of development.

Erythrocyte

• No nucleus is present in mature erythrocytes.

Characteristics of Erythrocyte

• Biconcave disc shape with a salmon-pink staining and a central pale area, facilitating gas exchange.