Haematopoiesis

Question 1

What are the three phases of the developmental pathway of erythropoiesis?

Answer 1

Phase 1 = ribosome synthesis

Phase 2 = Hgb accumulation

Phase 3 = ejection of nucleus

Question 2

Immature form of RBC

Answer 2

Reticulocyte

Question 3

Where is EPO used in erythropoiesis?

Answer 3

In the erythropoietin dependent path.

Question 4

Iron dependent for what stage of erythropoiesis?

Answer 4

From erythroblasts to reticulocytes

Question 5

How long can one RBC cell live?

Answer 5

100 - 120 days

Question 6

What stage is this?

“synthesis of hemoglobin “

Answer 6

Proerythroblast

Question 7

What stage is this?

“Nucleoli disappear”

Answer 7

Early normoblast

Question 8

What stage is this?

“Hemoglobin starts appearing”

Answer 8

Intermediate normoblast

Question 9

In the late normoblast, what happens?

Answer 9

The nucleus starts to disappear

Question 10

What happens to the reticulum in reticulocyte and matured RBC?

Answer 10

Reticulum is formed in reticulocyte but it disappears when matured.

Question 11

Role of vitamin C in erythropoiesis

Answer 11

Helps in iron absorption

Question 12

_________ is needed for absorption of vitamin B12

Answer 12

Intrinsic factor

Question 13

Androgen,_____, ______ and ACTH are hormones needed in erythropoiesis

Answer 13

Growth Hormone , Thyroxine

**RBC is slightly higher in male because androgen is for male sexual reproduction.

Question 14

Three types of vitamin B that is needed in erythropoiesis

Answer 14

Vitamin B6, B12 and B9 (folic acid)

Question 15

What is another name for erythropoetin?

Answer 15

Haemopoetin

Question 16

Erythropoietin (EPO) is a glycoprotein cytokine produced in the _________

Answer 16

Kidney

Question 17

Synthetic EPO is used clinically to treat ________

Answer 17

Anaemia

Question 18

_______ stimulates EPO production, which then stimulates erythrocyte production in bone marrow

Answer 18

A state of reduced oxygen carrying capacity (hypoxia)

Question 19

_______ are also used as illegal sports enhancing drugs

Answer 19

Synthetic EPO , so the athletes can increase number of RBC, which in turn increases aerobic capacity

Question 20

How EPO increases production of RBC?

Hint: Three ways it affects

Answer 20

1. promotes pronormoblast production
2. Shorten transition time in normoblast stage
3. promote early release of reticulocytes

Question 21

Name the six other sites where EPO has an effect on:

Answer 21

• Brain (protection form ischemia)
• endothelium (vascular tone)
• heart (protection form ischemia)
• myoblast (wound healing)
• white fat
• bone (remodeling)

Question 22

There is a decrease in cell size as RBC matures. True or False

Answer 22

True

Question 23

Two changes in intermediate normoblast

Answer 23

Loss of mitotic activity and hemoglobinization

Question 24

Change of RBC shape from _______ to _____ as it matures.

Answer 24

Globular , biconcave

Question 25

______ , _______ and ________ disappears as RBC matures.

Answer 25

Nucleus, mitochondria and RNA

Question 26

The staining of RBC will change as it matures. What changes?

Answer 26

From basophilic to eosinophilic

Question 27

Granulopoesis is the formation of _______ which are ____, ____ and _____.

Answer 27

granulated WBC, eosinophils, neutrophils and basophils.

Question 28

______ lymphocyte mature in bone marrow, _____ lymphocyte mature in thymus.

Answer 28

B lymphocyte in bone marrow, T lymphocyte in thymus

Question 29

Triggered monocytes turn into ______ in the tissues

Answer 29

Macrophage

Question 30

What is thrombopoeisis?

Answer 30

Formation of platelets

Question 31

Precursors of platelets are ________, _____ and ________.

Answer 31

Megakaryoblast, promegakaryocyte and megakaryocyte (in this order).

Then fragmentation of megakaryocyte turns into platelets

Question 32

Megakaryocytes will form pseudopodia which then becomes ______ and are released are fragmented into platelets.

Answer 32

Proplatelets

Question 33

Action of thrombopoietin (TPO) decreases slowly as we approach the end of thrombopoesis. True or False?

Answer 33

FALSE. In fact it becomes more dominant as we approach the end.

Question 34

Hematopoiesis outside of the bone marrow is called___________

Answer 34

Extramedullary hematopoiesis (EMH)

Question 35

In fetal development, extramedullary hematopoiesis (EMH) happens at the ______and ____.

Answer 35

Liver and spleen

** after this, progenitor cells would migrate to bone marrow

Question 36

In ______, hematopoietic factors (e.g_______) promotes EMH in the liver and spleen.

Answer 36

infection, Toll like receptor (TLR) ligands

** other than infection, marrow failure and increase demand of RBC also promotes EMH

Question 37

EMH can also occur in:

Answer 37

skin, lungs, lymph nodes, urogenital system, paraspinal spaces, retroperitoneal

Question 38

Give an example of active EMH and passive EMH each.

Answer 38

Active EMH = fetal development or infection (immune response)

Passive EMH = failed marrow

Question 39

Insufficient production or maturation of blood cells due to ______

Answer 39

Inadequate EMH

Question 40

Excessive EMH occurs in___

Answer 40

• autoimmune diseases

- chronic infection

Question 41

Jojo has an overly activated EMH, what are the possible presentations?

Answer 41

Jojo would have an enlarged organ depending on the site of EMH. Most likely hepatomegaly or splenomegaly or even hepatosplenomegaly.

Another presentation is the formation of calcified spicules at the skull under X-ray. Known as “Hair-on-end” appearance.