2. Hematopoiesis

Question 1

What is hematopoiesis ?

Answer 1

Production and differentiation of blood cells

Question 2

What is the classical marker for hematopoietic stem cells ?

Answer 2

CD 34

Question 3

The classical marker for hematopoietic stem cell CD 34 is also known as ?

Answer 3

Pluripotential cell (Mother cell)

Question 4

What is the Polyphyletic theory ?

Answer 4

This theory suggests that each of the blood cell lineages is derived from its own unique stem cell

Question 5

What is the Monophyletic theory ?

Answer 5

This theory suggests that all blood cells are derived from a single progenitor stem cell called a pluripotential stem cell

Question 6

Under the Monophyletic theory hematopoiesis involves the production of ___ that develop into committed ___ and finally ___

Answer 6

pluripotential stem cells -> progenitor cells (lymphoid or myeloid) -> mature blood cells

Question 7

What does CFU-GEMM stand for ?

Answer 7

colony forming unit granulocyte erythrocyte macrophage megakaryocyte

Question 8

What are the three phases of hematopoiesis ?

Answer 8

Mesoblastic/Megaloblastic -> Hepatic -> Medullary/Myeloid

Question 9

When does the mesoblastic phase of hematopoiesis begin ?

Answer 9

~19 days gestation

Question 10

What is the chief site of hematopoiesis during the mesoblastic phase ?

Answer 10

yolk sac

Question 11

When are the primitive nucleated erythroblasts formed during the mesoblastic phase ?

Answer 11

first 2 - 8 weeks of life

Question 12

What is the function of primitive nucleated erythroblasts ?

Answer 12

give out hemoglobin to satisfy the oxygen needs of the fetus

Question 13

What are the embryonic hemoglobin’s produces during the mesoblastic phase ?

Answer 13

Portland, Gower I, and Gower II

Question 14

When does the hepatic phase of hematopoiesis begin ?

Answer 14

6 weeks of gestation

Question 15

What is the chief site of hematopoiesis during the hepatic phase ?

Answer 15

liver

Question 16

What is produced during the hepatic phase ?

Answer 16

mainly red blood cells, also granulocytes, monocytes, and megakaryocytes

Hgb F; detectable Hgb A and A2

Question 17

When does the medullary phase of hematopoiesis begin ?

Answer 17

5th month of gestation

Question 18

What is the chief site of hematopoiesis during the medullary phase ?

Answer 18

bone marrow

Question 19

What does mainly red marrow indicate in a bone marrow ?

Answer 19

very active blood cell production

Question 20

The main sites of adult hematopoiesis is confined to the proximal ends of large flat bones which are ___

Answer 20

Ribs, sternum, vertebrae, pelvis

Question 21

What is the most common bone marrow collection site ?

Answer 21

Posterior superior iliac crest

Question 22

What are the indications for bone marrow examination ?

Answer 22

Neoplasia diagnosing and staging
Marrow failure: cytopenias
Metabolic disorders
Infections
Monitoring and treatment

Question 23

What is marrow cellularity ?

Answer 23

ratio of marrow cells to fat

Question 24

Normocellular marrow has a ___% hematopoietic cells

Answer 24

30-70%

Question 25

Hypercellular/hyperplastic marrow has ___% hematopoietic cells

Answer 25

> 70%

Question 26

Hypocellular/hypoplastic marrow has ___% hematopoietic cells

Answer 26

<30%

Question 27

Aplastic marrow has ___ hematopoietic cells

Answer 27

few or no

Question 28

• 40 - 120 um
• cytoplasm contains coarse clumps of granules aggregating into little bundles, which bud off from the periphery to become platelets

Answer 28

Megakaryocyte

Question 29

• 10 - 18 um

* nucleus is indented in a kidney bean shape and has coarse, clumped chromatin

Answer 29

Metamyelocyte

Question 30

• 40 - 50 um

* (+) nonspecific (alpha naphthyl acetate naphthyl butyrate) esterase

Answer 30

Macrophage

Question 31

• 12 - 25 um

* (+) chloroacetate esterase

Answer 31

Mast cells

Question 32

• waterbug/comet appearance

* synthesize new bone matrix

Answer 32

Osteoblast