Haemopoesis

Question 1

What is granulopoesis?

Answer 1

Production of granulocytes

Question 2

What is lymphopoesis?

Answer 2

Production of lymphocytes

Question 3

What is the life span of a neutrophil?

Answer 3

7-8 hours

Question 4

What is the life span of a platelet?

Answer 4

7-10 days

Question 5

What is the precursor cell of the platelet?

Answer 5

Megakaryocyte

Question 6

Why do megakaryocytes have polyploidy as high as 64n?

Answer 6

The nucleus divides many times without the cytoplasm dividing (endomitosis)

Question 7

What is the precursor cell of the neutrophil/granulocytes?

Answer 7

Myeloblast

Question 8

What does the word ‘blast’ in a precursor cell name mean?

Answer 8

A nucleated precursor cell

Question 9

What is a myelocyte?

Answer 9

Intermediate precursor between blast and neutrophils

Question 10

What is the Haemopoietic Progenitor Cell?

Answer 10

The precursor of precursor cells - has the ability to become the precursor cell of platelets, neutrophils or erythroblasts

Question 11

Where do the Haemopoietic Progenitor Cells and essentially all haemopoetic cells come from?

Answer 11

Haemopoietic stem cell

Question 12

How are haemopoetic stem cells maintained?

Answer 12

Undergo slightly asymmetrical division: creates one identical daughter cell and one slightly different cell which goes on to be haemopoietic progenitor cells

Question 13

What are haemopoetic stem cells derived from?

Answer 13

The mesoderm

Question 14

What is the significance of trabecular cells in bone?

Answer 14

Gives bone marrow ability to develop alongside actual bone cells
Minute projections of trabeculae throughout the metaphysis allow this

Question 15

How do blood cells leave the bone marrow?

Answer 15

Exits through a fenestration in the endothelial cells of the sinusoids, which are specialised fenestrated venules

Question 16

What is red and yellow marrow?

Answer 16

Red - haematopoetically active

Yellow - fatty and inactive marrow

Question 17

How does the composition of red and yellow marrow change with age?

Answer 17

Children have lots of red marrow

Amount of yellow marrow increases with age

Question 18

What can a granulocyte differentiate to become?

Answer 18

Eosinophil
Basophil
Neutrophil

Question 19

What are the causes of neutrophilia?

Answer 19

Inflammation
Bacterial infection
Tissue necrosis
Acute haemorrhage
Neoplasia

Question 20

What are the causes of eosinophilia?

Answer 20

Asthma
Helminthic infection
Severe eczema

Question 21

What are the causes of basophilia?

Answer 21

Polycythaemia rubra vera

Chronic myeloid leukaemia

Question 22

Why is it often difficult to see the nucleus of basophils on blood film?

Answer 22

Nucleus obscured by blue/black granules rich in histamine and heparin

Question 23

What kind of hypersensitivity reaction does degranulation of a basophil cause?

Answer 23

Type 1

Question 24

How does degranulation of a basophil occur?

Answer 24

IgE receptors on the cell surface allow specific antibody/antigen interactions to cause degranulation

Question 25

What might increased levels of serum mast cell typtase indicate?

Answer 25

Systemic mastocytosis | A recent anaphylactic reaction

Question 26

Where do lymphocytes arise and develop?

Answer 26

Arise in bone marrow | Develop in primary lymphoid organs i.e. thymus and bone marrow

Question 27

What is the importance of IgG and IgM in confirmatory testing?

Answer 27

IgM specific antibodies confirm recent infection | IgG specific antibodies confirm past infection

Question 28

What are monocytes the precursor to?

Answer 28

Macrophages

Question 29

What are the three main locations of haemopoesis in adults?

Answer 29

Vertebrae Sternum Ribs

Question 30

What are the compartments of the bone marrow?

Answer 30

``` Cellular: - haemopoeitic cells - non-haemopoietic cells Vascular elements Connective tissue matrix ```