HLS histology 2 : Hematopoiesis II

The growth factor that produced by cells in the kidneys and stimulates production of mRNA for globins is ….

The glycoprotein erythropoietin

stages of Erythropoiesis?

1-Pluripotential stem cell ——> myeloid multipotential

2-Erythrocyte colony forming unit (CFU-E) (progenitor)

3-Pro-erythroblast

4-Basophilic erythroblast

5-Polychromatophilic erythroblast

6-Orthochromatophilic erythroblast (normoblast)

7-Reticulocyte

in erythropoiesis , the cytoplasm is deeply basophilic in …..

Basophilic erythroblast

in erythropoiesis , the cytoplasm shows areas of acidophilia and basophilia in …

Polychromatophilic erythroblast

(T/F)

in the cytoplasm of orthochromatophilic erythroblast (normoblast) there is no ribosomes and polyribosomes

false

The cytoplasm of orthochromatophilic erythroblast contains ribosomes and polyribosomes.

in erythropoiesis ,The nucleus condensed pyknotic and extruded peripherally in…

Orthochromatophilic erythroblast

(T/F)

Reticulocyte is non-nucleated immature erythrocyte.

True

Reticulocyte is stained with…

Brilliant cresyl blue

In erythropoiesis , what changes will happen to the following:

1- cells size

2- nucleus

3- ribosomes and polysomes

4- hemoglobin

5- Mitochondria and other cell organelles

1) The cell size becomes smaller

2) The nucleus becomes smaller, condensed, pyknotic and finally extruded from the cell

3) Decrease in free ribosomes and polysomes (decrease of basophilia)

4) increase of hemoglobin (increased acidophilia)

5) Mitochondria and other cell organelles gradually disappear

shape of the nucleus in megakaryoblast …

large kidney-shaped nucleus with numerous nucleoli

The characteristic of megakaryoblast nucleus is…

- polyploidy nucleus [multiple sets of haploid number (23 chromosomes)

- endomitosis (multiple nuclear divisions without separation)

(T/F)

Both megakaryocyte and megakaryoblast have basophilic cytoplasm

True

shape of the nucleus in megakaryocyte …

Irregular lobulated nucleus with coarse chromatin

The process of Megakaryopoiesis is driven by …. hormone

Thrombopoietin

Platelets originate by …..

Fragmentation of cytoplasm of mature megakaryocytes

Whole process :

With maturation of megakaryocytes, they extend several long, wide branching processes called proplatelets These cellular extensions penetrate the sinusoidal endothelium and are exposed in the circulating blood of the sinusoids.

 Numerous demarcation channels formed throughout the cytoplasm (fracture lines) for the release of platelets

 Platelets originate by fragmentation of cytoplasm of mature megakaryocytes and the remainder of cells degenerated and phagocytosed by macrophages.

stages of Granulopoiesis?

1-Pluripotential stem cell ——> myeloid multipotential

2-Granulocyte colony forming unit (CFU-G)

3- Myeloblast

4- Promyelocyte

5- Myelocyte

6-Metamyelocyte

initial production of specific granules occur in which stage of granulopoiesis?

the myelocyte stage

intermediate stage Before granulocytes complete its maturation called,,,

the band cell

stages of monocytopoiesis?

1- Pluripotential hematopoietic stem cell ——> myeloid multipotential stem cell

2- Colony forming unit of monocyte (CFU-M) (M-CSF)

3- Monoblasts: identical to the myeloblast morphologically

4- Promonocytes: a large cell with basophilic cytoplasm and a large, slightly indented nucleus

5- Monocytes: circulate for three days then enter C.T and become macrophages.