Introduction to haematology

Question 1

What is the term used to describe the production of red blood cells?

Answer 1

Haemopoiesis/haematopoiesis

Question 2

Where does haematopoiesis occur in embryos?

Answer 2

Yolk sac then liver then marrow 3rd to 7th month = spleen

Question 3

Where does haematopoeisis occur at birth?

Answer 3

Mostly bone marrow liver and spleen when needed

Question 4

Where does haematopoeisis occur from birth to maturity?

Answer 4

Number of active sites in bone marrow decreases but retain ability for haematopoiesis

Question 5

Where does haematopoeisis occur in adults?

Answer 5

Bone marrow of skull, ribs, sternum, pelvis, proximal ends of femur

Question 6

Are the majority of stem cells actively dividing or in a quiescent state?

Answer 6

Quiescent state

Question 7

Name the primary haemaopoietic stem cell

Answer 7

LT-HSC = long term-haematopoietic stem cell

Question 8

What can multipotent progenitor cells (MPP) divide into?

Answer 8

Either CMP (common myeloid progenitor) or CLP (common lymphoid progenitor)

Question 9

What can common myeloid progenitor cells divide into?

Answer 9

Megakaryocyte-erythrocyte progenitor (MEP) or granulocyte-monocyte progenitor (GMP)

Question 10

What can common lymphoid progenitor cells divide into?

Answer 10

Pro-T cell, Pro-NK cell (NK=natural killer) or Pro-B cell

Question 11

What do pro-T, pro-B and pro-NK cells divide into respectively?

Answer 11

T-cells, B-cells an natural killer cells

Question 12

What can MEP cells divide into/

Answer 12

Either erythrocytes or platelets

Question 13

What can GMP cells divide into?

Answer 13

Granulocytes or macrophages

Question 14

What cell type can both CMP and CLP cells divide into and what does this cell type differentiate into?

Answer 14

Pro-DC which becomes a dendritic cell

Question 15

What are immature red blood cells called?

Answer 15

Reticulocytes

Question 16

Why are granulocytes named granulocytes?

Answer 16

They contain granules that are easily visible on light microscopy

Question 17

How are the different types of granulocyte named?

Answer 17

Based on their uptake of stains (eosin and basic dyes) i.e. basophils take up basic dyes, eosinophils take up eosina and neutrophils have neutral uptake

Question 18

Neutrophils are polymorphs, what does this mean?

Answer 18

They have a segmented nucleus

Question 19

What is the function of neutrophils?

Answer 19

Phagocytose invaders, kill with granule contents and die in the process, attract other cells, increased by body stress e.g. infection, trauma. They have a short life in circulation

Question 20

Describe the structure of eosinophils

Answer 20

Usually bi-lobed, bright orange/red granules

Question 21

What is the function of eosinophils?

Answer 21

Fight parasitic infections, involved in hypersensitivity (allergy), often elevated in patients with allergic conditions e.g. asthma

Question 22

Describe the structure of basophils

Answer 22

Large deep purple granules obscuring nucleus (they are infrequent in the circulation)

Question 23

What is the function of basophils?

Answer 23

Circulating version of tissue mast cell, mediates hypersensitivity reactions, Fc Receptors bind IgE, granules contain histamine!

Question 24

Describe the structure of monocytes

Answer 24

Large single nucleus, faintly staining granules, often vacuolated

Question 25

What is the function of monocytes?

Answer 25

Circulate for a week then enter the tissues to become macrophages, phagocytose invaders, attract other cells. More long lived than neutrophils

Question 26

Describe the structure of lymphocytes

Answer 26

Mature - small with condensed nucleus and rim of cytoplasm Activated - large with plentiful blue cytoplasm extending round neighbouring red cells on the film, nucleus has more open structure

Question 27

What is the function of lymphocytes?

Answer 27

Respond to infection - brains of the immune system

Question 28

How do you identify the more primitive blood cell precursors?

Answer 28

Immunophenotyping and bio-assays

Question 29

What is a common site for bone marrow aspiration and biopsy?

Answer 29

Posterior iliac crests