Erythropoiesis - Stages Of Differentiation Of RBCs Flashcards
What are the 2 types of cells that MHSCs differentiate into?
CFU-S (Colony-forming-unit - spleen)
LSC (Lymphoid stem cell)
What are the 2 types of cells that LSCs give rise to?
T lymphocytes
B lymphocytes
What is the first call that can be identified as belonging to the RBC series? What are they formed from?
Pro erythroblast.
CFU-E stem cells
(Figure 33-3)
What are the different stages of RBC differentiation in order?
Proerythroblast ⬇️ Basophil erythroblast ⬇️ Polychromatophil erythroblast ⬇️ Orthochromatic erythroblast ⬇️ Reticulocyte ⬇️ Erythrocytes
What are the cells obtained after differentiation of proerythroblasts called?
Why are they called that?
Describe the nature of the chromatin of the nucleus.
Basophil erythroblasts
because they stain with basic dyes due to intensely basophilic cytoplasm as a readily of increased number of ribosomes.
It’s a coarse network of dense heterochromatin
In which stage of RBC differentiation does haemoglobin first appear?
Polychromatophil erythroblast
With each division in the differentiation process, what happens to the basophilia and the hemoglobin content?
Basophilia decreases
Hemoglobin quantity increases (acidophilic)
How did Polychromatophilic erythroblasts get their name?
Since the cytoplasm of those cells take varying amounts of acid and basic components of the Wright stain, it shows mixed colors varying from purplish-blue to a light pink or gray.
What is another name for Orthochromatophilic Erythroblasts?
Normoblasts
How are organelles present in normoblasts?
What happens to the nucleus after active mitosis.
Ribosomes have almost disappeared from the cytoplasm
Golgi apparatus and mitochondria are seen undergoing degeneration
Nuclei become very much shrunken (pyknotic) and no further division is possible. Finally, it is extruded from the cell.
Why are immature erythrocytes called ‘reticulocytes’?
When they are stained in blood smears by special dyes like cresyl blue, the cytoplasm shows a delicate bluish network (reticulum)
What is the reason behind the basophilic reticulum seen in the cytoplasm of reticulocytes?
RNA of the ribosomes
When reticulocytes are are released from the red bone marrow into the circulating blood, they undergo maturation. How long is the maturation period?
24 to 48 hours
What is the percentage of reticulocytes in the circulating blood, under normal conditions?
0.5 to 2% (slightly less than 1%)
How do reticulocytes pass from the bone marrow into the blood capillaries?
By diapedesis (squeezing through the pores of the capillary membrane)
