Haematopoiesis

Question 1

What is haematopoeisis?

Answer 1

The formation of blood cells from stem cells.

Question 2

Where does haematopoeisis 1st occur in the fetus?

Answer 2

The yolk sac,then spleen & liver

Question 3

Where does haematopoeisis occur in infants and adults?

Answer 3

Infants-bone marrow of all bones
Adults-bone marrow of ribs,vertebrae,cranium and pelvis

Question 4

How dos the bone marrow produce these blood cells?

Answer 4

By interaction with cells such as macrophages,fibroblasts,endothelia fat cells via direct contact or growth factors

Question 5

What are the growth factors involved in haematopoeisis?

Answer 5

Colony stimulating factors— IL3
GM-CSF(Granulocyte Macrophage)
Erythropoietin{EPO}—RBCproduction
Thrombopoietin{TPO}—Megakaryocytes(platelets source) production

Question 6

What happens during the process of granulopoiesis?

Answer 6

Decrease in cell size,change in nuclear shape,accumulation of granules

Myeloblast-Promyelocyte-Myelocyte-Metamyelocyte-Band-CELL(neutrophil,basophil,eosinophil)

Question 7

What’s thrombopoiesis?

Answer 7

*The formation of platelets from megakaryocytes

*TPO is produced by the liver,kidneys,endothelial cells & bone marrow stromal cells.

*TPO conc is inversely proportional to platelets no.—platelets binds to the TPO inhibiting production off more platelets.

Question 8

Where are platelets stored and destroyed when the age out?

Answer 8

Storage-SPLEEN
Destroyed-Liver & Spleen by macophages

Question 9

Name all the steps in erythropoiesis:

Answer 9

Proerythroblast-Basophilic erythroblast-Polychromatophilic erythroblast-Normablast-Reticulocyte-Mature erythrocytes

Question 10

WHERE IS ERYTHROPOIETIN produced?

Answer 10

In the KIDNEYS and for fetus,the Liver