Introduction to Haematology

Question 1

What is the definition of haematology?

Answer 1

Biology and pathology of the cells that normally circulate in the blood

Question 2

What is the definition of haemopoiesis?

Answer 2

physiological developmental process that gives rise to the cellular components of the blood - starts in bone marrow
single multipotent haemopoietic stem cell can divide and differentiate to form different cell lineages

Question 3

What are the features of Haemopoietic stem cells?

Answer 3

differentiates into all lineages
Long term activity throughout the lifespan of the individual
Self renewal

Question 4

What are the 4 types of self renewal that can occur?

Answer 4

symmetric self revewal - duplication of identical cells to increase volume
asymmetric self-renewal - forms half stem and half mature cells
lack of self renewal - forms fully differentiated cells
lack of self renewal - does not differentiate

Question 5

What are the two Haemopoietic Lineages?

Answer 5

Myeloid - WBC, RBC, platelets

lymphoid - B and T lymphocytes

Question 6

What is another name for precursor cells?

Answer 6

committed cells

Question 7

Where does haemopoiesis originate from?

Answer 7

starts on day 27
aorta gonad mesonephos region - vessel wall
stems cells then travel in the bloodstream and migrate into the foetal liver and that becomes the site of haemopoiesis

Question 8

What is anaemia?

Answer 8

reduced red cells

Question 9

What is polycythaemia?

Answer 9

raised red cells

Question 10

What is relative polycythaemia?

Answer 10

plasma volume is reduced

Question 11

What is the lifespan of the red blood cell?

Answer 11

120 days in the blood

Question 12

What shape is a red blood cell?

Answer 12

bi-concave

Question 13

What are the 3 types of ganulocytes?

Answer 13

neutrophils
eosinophils
basophils

Question 14

What is the function of neurophils?

Answer 14

phagocyte

engulfs bacteria

Question 15

What is neutophilia and when does it occur?

Answer 15

increased number of neutrophils
bacterial infection
inflammation

Question 16

What is neutropenia and when can it occur?

Answer 16

decreased number of neutrophils
side effect of a drug - chemo
autoimmune disease

Question 17

what is eosinophilia and when can it occur?

Answer 17

increased number of eosinophils
parasitic infection - schistosomiasis
allergies
drugs e.g. aspirin

Question 18

what is basophilia and when can it occur?

Answer 18

increased number of basophilia

chronic myeloid leukaemia

Question 19

What are monocytes?

Answer 19

phagocytic
antigen presenting cells
migrate to tissues the identified as macrophages or histiocytes

Question 20

what is monocytosis and when can it occur?

Answer 20

increased number of monocytes

TB

Question 21

What cells are lymphocytes?

Answer 21

Natural killer cells
B lymphocytes
T lymphocytes
Plasma cells

Question 22

What do natural killer cells do?

Answer 22

innate immune system
large granular lymphocytes
recognises ‘non self’ cells i.e. viruses

Question 23

What do B lymphocytes do?

Answer 23

humoral immunity
adaptive immune system
antigen specific antibody production

Question 24

What do T lymphocytes do?

Answer 24

adaptive/cell mediated immune system
rearrange T cell antigen receptors
interact with B cells and macrophages
regulate immune response
uses cytotoxicity

Question 25

What is lymphocytosis and when can it occur?

Answer 25

increased number of lymphocytes chronic lymphocytic leukaemia glandular fever - atypical

Question 26

What is lymphopenia and when can it occur?

Answer 26

post bone marrow transplant

Question 27

What is plasmacytosis and when can it occur?

Answer 27

increased number of plasma cells infection myeloma

Question 28

What do platelets do?

Answer 28

forms part of blood clotting system | aggregate to plug holes in damaged blood vessels

Question 29

where are platelets derived from?

Answer 29

bone marrow megakaryocytes

Question 30

What is microcytic hypochromic anaemia?

Answer 30

low MCV | low MCH

Question 31

When can microcytic hypochromic anaemia occur?

Answer 31

iron deficiency thalassaemia lead poisioning Anaemia of some chronic diseases

Question 32

What is normocytic normochromic anaemia?

Answer 32

MCV 80-95 (normal) MCH >27 (normal) Hb low

Question 33

When can normocytic normochromic anaemia occur?

Answer 33

``` Many haemolytic anaemias Anaemia of chronic disease (some cases) After acute blood loss Renal disease Mixed deficiencies Bone marrow failure (e.g. post-chemotherapy, infitration by carcinoma etc) ```

Question 34

What is macrocytic anaemia?

Answer 34

MCV > 95 (larger RBC)

Question 35

When can macrocytic anaemia occur?

Answer 35

Megaloblastic: Vitamin B12 or folate deficiency | Non-megaloblastic: alcohol, liver disease, myelodysplasia, aplastic anaemia etc