Haematopoiesis

Question 1

What is haematopoeisis?

Answer 1

Production of blood cells

Question 2

What is included in the haematopoietic system?

Answer 2

Bone marrow
Liver 
Spleen 
Lymph nodes 
Thymus

Question 3

What are blood islands?

Answer 3

They are structures formed in the yolk sac in 3rd week of gestation and produce primative blood cells which migrate to liver and spleen

Question 4

What is the chief site of haematopoiesis from 6 weeks to 7 months?

Answer 4

Blood islands

Question 5

What becomes the chief sites of haematopoiesis from 7 months?

Answer 5

Bone marrow

Question 6

At birth is their a lot of haematopoeisis?

Answer 6

Yes present in nearly every bone, whereas as child grows the active red marrow is replaced by fat (yellow marrow)

Question 7

Where is haematopoiesis confined to in adult?

Answer 7

Central skeleton and proximal ends of long bone

Question 8

What could pathological process interfering with normal haematopoiesis result in?

Answer 8

Resumption of haematopoietic activity in the spleen or liver

-Extramedullary haematopoiesis

Question 9

2 key properties of blood cells?

Answer 9

Self-renewal and proliferation and differentiation into mature blood cells
Through intermediate progenitor cells which have lost ability to self-renew

Question 10

Classification of progenitor cells?

Answer 10

Lymphoid and myeloid

Question 11

Lymphoid means?

Answer 11

Gives rise to lymphocytes

Question 12

Myeloid give rise to?

Answer 12

Non-lymphocytes

Question 13

Blast cells?

Answer 13

Nucleated precurosr cells

Question 14

Examples of blast cells?

Answer 14

Lymphoblasts
Erythroblasts
Myeloblasts

Question 15

Myelocytes?

Answer 15

Nucleated precursor between neutrophils and blasts

Question 16

Differentiation

Answer 16

Process by which descendants commit to one or more lineages

Question 17

Self-renewal?

Answer 17

Property of stem cells where stem cells can make more stem cells. this is lost in descendants

Question 18

Estimated bone marrow cellularity?

Answer 18

Subtract someone’s age from 100

Question 19

Where would bone biopsy be taken from an adult?

Answer 19

Axial skeleton- iliac crest or sternum

Question 20

Young children bone biopsy?

Answer 20

Tibia shaft

Question 21

How do we assess haematopoiesis from non-lymphoid mature cells?

Answer 21

FBC, Cell indices and morphology

Less commonly: bone marrow examination

Question 22

Assessing haematopoiesis in mature lymphoid cells?

Answer 22

• Immunophenotyping to look at expression of antigens indicating lineage or stage of development
• Cytochemistry (rarely used)

Question 23

Testing haematopoiesis in stem cells/progenitor cells?

Answer 23

Immunophenotyping