Haematopoisis

Question 1

hematopoiesis in the 2nd week of development is by __________

Answer 1

Yolk sack

Question 2

Hematopoiesis in the 6th week of development is by __________

Answer 2

Liver

Question 3

Hematopoiesis in the 6-8th week until 8th month of development is by ________

Answer 3

Spleen

Question 4

Hematopoiesis after birth is by ____________

Answer 4

Bone marrow

Question 5

Types of bone marrow

Answer 5

1. Red bone marrow .

2. White bone marrow .

Question 6

Why we call it ( red bone marrow ) ?

Answer 6

Due to large amount of blood and hematopoietic cells .

Question 7

Why we call it ( yellow bone marrow ) ?

Answer 7

Due to large amount of adipose cells and absence of hematopoietic cells .

Question 8

Red bone marrow histology

Answer 8

1. Stroma .
   a. Adventitial reticular cells .
   b. Macrophages .
2. Hematopoietic cord .
3. Sinusoidal capillaries .
4. Adipocytes .

Question 9

Sinusoidal capillaries histology

Answer 9

1. Diameter is about 45-80um .
2. Endothelial cells .
3. Reticular fibers .
4. Incomplete basal lamina .

Question 10

The function of bone marrow

Answer 10

1. Blood production .
2. Rbc destruction .
3. Immune system ( macrophages & plasma cells )
4. Storage of Fe .
5. Production of cytokines & growth factors .

Question 11

Myeloid tissue if responsible of production of :

Answer 11

1. Erythrocytes .
2. Platelets .
3. Granulocytes .
4. Monocytes .

Question 12

Lymphatic tissue organs

Answer 12

1. Thymus .
2. Lymph nodes .
3. Spleen .

Question 13

All blood cells are arise from

Answer 13

Hemocytoblast ( pluripotent stem cell )

Question 14

Hemocytoblast description

Answer 14

1. 15-20um in diameter .
2. Deep basophilic cytoplasm ( a lot of ribosomes ) .
3. Rounded or oval nucleus contain 2-5 nucleoli .

Question 15

Erythropoiesis is regulated by

Answer 15

Erythropoietin which secreted by kidney .

Question 16

Erythropoietic cells lack of nucleoli

Answer 16

1. Polychromatophilic erythroblast .
2. Normoblast .
3. Reticulocyte .
4. Mature rbc .

Question 17

Erythropoietic cells don’t have nucleus

Answer 17

1. Reticulocyte .

2. Mature rbc .

Question 18

Erythropoietic cells have basophilic cytoplasm

Answer 18

1. Proerythroblast .

2. Basophilic erythroblast .

Question 19

Erythropoietic cells have acidophilic cytoplasm

Answer 19

1. Normoblast .
2. Reticulocyte .
3. Mature rbc .

Question 20

What are the changes happen through erythropoiesis ?

Answer 20

1. Decrease in the size from 14 to 7.5 .
2. Lack of nucleus gradually .
3. Lack of nucleolus gradually .
4. Cytoplasm converted from baso to acidophilic .
5. Lack of ribosome & mitochondria .
6. Increase in amount of Hb .

Question 21

Large nucleus ( 80% of cell volume )

Answer 21

Proerythroblast

Question 22

Chromatin arranged as ( clock face ) / irregular

Answer 22

Basophilic erythroblast

Question 23

Chromatin arranged as ( checker board ) /regular

Answer 23

Polychromatophilic erythroblast

Question 24

Round , small & dense chromatin / about 1/4 of cell volume

Answer 24

Normoblast ( orthrochromatophilic erythroblast )

Question 25

Contains only Hb

Answer 25

Mature rbc

Question 26

Filled with Hb & cluster of ribosomes

Answer 26

Reticulocyte

Question 27

Hb starts to appear

Answer 27

Basophilic erythroblast

Question 28

Does not contain Hb

Answer 28

Proerythroblast

Question 29

Megakaryoblast description

Answer 29

1. 25-30um . 2. Oval nucleus . 3. Homogenous & basophilic cytoplasm . 4. Many mitosis division . 5. Nucleus is multilobulated .

Question 30

Megacaryocyte description

Answer 30

1. 30-100um in diameter . 2. Multilobular nucleus . 3. Slightly acidophilic . 4. Few ribosomes , smooth & RER .

Question 31

Proplatelets

Answer 31

Long & branched processes which penetrate the sinusoidal endothelium to lie within circulation .

Question 32

Granulopoietic cells have no nucleoli

Answer 32

1. Metamyelocyte . 2. Band cell . 3. Mature granular wbc .

Question 33

Granulopoietic cell has no granules

Answer 33

Myeloblast

Question 34

What is the changes during granulopoiesis

Answer 34

1. Decrease in diameter . 2. Nucleus ( round —> oval —> kidney —> horse shoe —> curved rode —> lobulated . 3. Condensing of chromatin . 4. Nucleoli disappear gradually . 5. Basophilic cytoplasm —> pale bluish - pink . 6. Formation of granules . Decrease in organelles ( RER , golgi , mitochondria & ribosome ) .

Question 35

Promonocyte description

Answer 35

1. 16-18um in diameter . 2. Oval or kidney & eccentric nucleus . 3. Basophilic cytoplasm . 4. No specific granules . 5. Large amount of organelles .

Question 36

Lymphoblast description

Answer 36

1. Large round cell . 2. Basophilic cytoplasm . 3. No granules . 4. Rounded nucleus . 5. Dense chromatin . 6. 2-3 nucleoli .

Question 37

Polylymphocte

Answer 37

1. Smaller than lymphoblast . 2. Basophilic cytoplasm . 3. Dense chromatin . 4. Nucleoli can not be seen .