Introduction to haematology

Question 1

What is haemopoiesis?

Answer 1

Physiological developmental process giving rise to cellular components of blood

Question 2

What is the first cell in haemopoiesis?

Answer 2

Haemopoietic stem cell

Question 3

What are the 4 facts of haemopoietic stem cells?

Answer 3

Symmetric self renewal - increase stem cell pool, no generation of differentiated progeny

Asymmetric self renewal - maintenance of stem cell pool and generation of differentiated progeny

Lack of self renewal - increased generation of differentiated progeny, reduced stem cell population

Lack of self renewal - maintenance of stem cell pool RESTING STATE

Question 4

What are the characteristics of haemopoietic cells that make them suited for their function/

Answer 4

Differentiation potential for all lineages
High proliferative potential
Long term activity throughout lifespan
Self renewing

Question 5

What are the 2 broad lineages of haemopoiesis?

Answer 5

Myeloid - granulocytes, erythrocytes, platelets

Lymphoid - B lymph, T lymph, NK cells

Question 6

When does haemopoiesis first start and where?

Answer 6

Day 27

AGM (aorta gonad mesonephros)

Question 7

At day 40, haemopoiesis disappears at the AGM, why?

Answer 7

Migration of haemopoietic stem cells from AGM to foetal liver (which becomes site of haemopoiesis)

Question 8

What is the lifespan of a erythrocyte?

Answer 8

120 days

Question 9

What do the following terms mean?
Anaemia
Polycythaemia
Relative polycythaemia

Answer 9

• Reduced RBCs
• Increased RBCs
• Reduced plasma volume (therefore ratio of RBC:plasma increases)

Question 10

What is the term meaning reduced number of neutrophils?

Answer 10

Neutropaenia

Question 11

What is the term meaning increased neutrophils?

Answer 11

Neutrophilia

Question 12

How long do neutrophils last in the bloodstream?

Answer 12

4-6 hours

Question 13

What circumstances does eosinophilia occur?

Answer 13

• Parasitic infections

- Allergies

Question 14

What condition could basophilia indicate?

Answer 14

Chronic myeloid leukaemia

Question 15

What is the term meaning increased number of monocytes?

Answer 15

Monocytosis

Question 16

What could increased number son monocytes in the blood indicate

Answer 16

Infection e.g. TB

Question 17

What do Natural killer cells do?

Answer 17

Large granular cells (innate immunity) that recognise non-self cells

Question 18

What are the function of B lymph?

Answer 18

Part of adaptive immune system, they rearrange immunoglobin genes to enable specific antibody production

Question 19

What are the function of T cells?

Answer 19

T helper and Cytotoxic T cells

Question 20

What does lymphocytosis mean?

Answer 20

Increased number of lymphocytes

e.g. atypical lymphocytes of glandular fever; chronic lymphocytic leukaemia

Question 21

What does lymphopenia mean?

Answer 21

Reduced number of lymphocytes e.g. post bone marrow transplant

Question 22

What does plasmacytosis mean?

Answer 22

Increased number of plasma cells e.g. infection, myeloma

Question 23

What cells do platelets cells originate from?

Answer 23

Megakaryocyte

Question 24

What are the 4 main subdivisions of haematology?

Answer 24

Coagulation
Malignant
Non-malignant
Transfusion

Question 25

What information can you get from a FBC?

Answer 25

``` Hb conc Red blood cell count - Mean cell volume - mean cell Hb Platelet White blood cell ```

Question 26

What are the normal FBC ranges?

Answer 26

``` Hb (g/l)male = 135-180; F 115-160 WBD 4-11 Platelets - 150-400 MCV - 78-100 MCH - 27-32 ```

Question 27

What tis the information you receive from a coagulation screen?

Answer 27

Prothrombin time Activation partial thromboplastin time Thrombin time

Question 28

When blood is extracted, how is it treated in the tube?

Answer 28

EDTA anticoagulant

Question 29

What is meant by test sensitivity?

Answer 29

Degree to which tests picks up TRUE ABNORMALITIES (i.e. true negatives) TP/(TP+FN)

Question 30

What does test specificity tell us?

Answer 30

The proportion of normal test results correctly classified by a test TN/(TN+FP)

Question 31

What are the three main types of anaemia?

Answer 31

Microcytic (smaller), homochromic (paler)- (low MCV, MCH) normocytic, norochromic (normal MCV, MCH, but actual Hb is low) Macrocytic (greater MCV)

Question 32

What can cause microcytic hypo chromic anaemia?

Answer 32

Iron deficiency* Thalassaemia Lead poisoning

Question 33

What can cause normocytic, norochromic anaemia?

Answer 33

Acute blood loss Renal disease Bone marrow failure Mixed deficiencies (folate, B12, iron)

Question 34

What can cause macrocytic anaemia?

Answer 34

Megaloblastic (abnormality of division deficiency/proliferation in haemopoetic) - vit B12, folate deficiency Non-megaloblastic - alcohol abuse, liver disease