Overview of Hematopoiesis

Question 1

Name 6 distinct stages of granulocyte maturation?

Answer 1

Myeloblast, Promyelocyte, Myelocyte, Metamyelocyte, Band, Segmented Neutrophil

Question 2

Name 6 important features in distinguishing various stages of myeloid cells (1-2-3)?

Answer 2

1) nuclear: cytoplasmic ratio
2a) color of granules
2b) cytoplasmic basophilia
3a) shape of nucleus
3b) presence of nucleoli
3c) chromatin pattern

Question 3

What determines color of granules (granulocyte lineage)?

Answer 3

• Nonspecific esterase: early stage of differentiation (Azurephilic, burgundy)
• Specific esterase: Late stage differentiation -> a) Eosinophilic: glassy pink red; b) Basophilic: deep blue; c) Neutrophil: tiny salmon pink

Question 4

When are nucleoli present?

Answer 4

Early stage, as pale spots in nucleus

Question 5

What happens to shape of nucleus?

Answer 5

For granulocyte: stays round until metamyelocyte; then indented or kidney -> band (equal width) -> segmented
For erythoid: stays round

Question 6

What happens to chromatin pattern?

Answer 6

Must distinguish between fine-lacy and clumped (dark, ropey with empty white spots). Chromatin goes from being open and active to condensed and inactive through stages of differentiation.

Question 7

What does cytoplasmic color indicate?

Answer 7

Early it is full of RNA or ER which stains basophilic (blue) and later it is pinker due to presence of proteins and less RNA content:
In erythroid: the middle stage is grey cytoplasm because of blue and pink mix.

Question 8

What are 3 stages of Monocyte maturation?

Answer 8

1) Monoblast 2) Promonocyte 3) Monocyte
* similar to granulocyte maturation; except the presence of vaculoles throughout and cytoplasmic color from blue to blue-gray to grey-clear

Question 9

What are the 6 stages of Erythroid maturation?

Answer 9

1) Pronormoblast 2) Basophilic Normoblast 3) Prochromotophilic normoblat 4) Orthochromic normoblast 5) Reticulocyte 6) RBC

Question 10

What are 3 stages of Megakaryocyte maturation?

Answer 10

1) Megakaryoblast 2) Megakaryocyte 3) Platelets

* cytoplasmic blebs are unique to this lineage

Question 11

What are 4 branches of myeloid differentiation?

Answer 11

1) Granulocytic (Neutros, Eos, Basos) 2) Monocytic 3) Erythroid 4) Megakaryocytic