Haematology

Question 1

What does blood contain?

Answer 1

RBCs, WBCs, platelets and plasma

Question 2

What does plasma contain?

Answer 2

Water, electrolytes, glucose, lipids, metabolites, gases, hormones, drugs and plasma proteins.

Question 3

What are the plasma proteins?

Answer 3

Albumins, globulins and fibrinogen.

Question 4

What do albumins do?

Answer 4

— Used in transport, e.g. of fatty acids.

— Provide colloidal osmotic pressure (level too low causes water to stay in the tissues and hence swelling).

Question 5

What do globulins do?

Answer 5

— Used in transport

— Involved in the coagulation process (clotting, precursors to hormones, defence).

Question 6

What does fibrinogen do?

Answer 6

— Involved in clotting.

Question 7

What is the blood serum?

Answer 7

Coagulated blood plasma.

Question 8

What are the features of erythrocytes?

Answer 8

Discoid, large SA:vol ratio, 8micrometres, no nucleus, 35% haemoglobin, lifespan of 120 days.

Question 9

What are the different types of leucocytes?

Answer 9

Neutrophils, eosinophils, basophils, monocytes and lymphocytes.

Question 10

Describe info about neutrophils.

Answer 10

Also called polymorphs. Stained by neutral dye. Involved in phagocytosis of microorganisms.

Question 11

Describe info about eosinophils.

Answer 11

Stained by eosin. Associated with parasite killing and inflammation (allergic asthma).

Question 12

Describe info about basophils.

Answer 12

Stained by basic dye. Release histamine in hypersensitivity reactions.

Question 13

Describe basic info about monocytes.

Answer 13

Are phagocytic, the leave the blood and become macrophages in tissues- “reserve macrophages”

Question 14

What is the main lymphocyte function?

Answer 14

They produce antibodies.

Question 15

What are platelets?

Answer 15

Also known as thrombocytes, are non-nucleated cellular fragments involved in clot formation, haemostasis and injured tissue repair.

Question 16

What is the name for blood cell production and where does it occur?

Answer 16

Haemopoiesis. Foetus and neonate haemopoiesis occurs in the liver and spleen. Neonate, child and adult haemopoiesis occurs in the bone marrow.

Question 17

What molecules are involved in the tight regulation of platelets?

Answer 17

Thrombophlebitis- a polypeptide produced by the liver which gives rise to platelets when needed. Megakaryocytes are a precursor to platelets.

Question 18

What molecules are involved in the tight regulation of red blood cells?

Answer 18

Erythropoietin (EPO)- produced in the kidney, which signals the bone marrow to produce more RBCs if needed (e.g. in certain altitudes).

Question 19

How many daughter cells can 1 pluripotent stem cell give rise to and how can this cause problems?

Answer 19

1 million daughter cells. This can cause problems as one mutation can create tons of abnormal cells.

Question 20

How is WBC production controlled?

Answer 20

By colony-stimulating factors (CSFs). These are peptides produced in the body in response to infection. Interleukins also play a role.

Question 21

What are recombinant CSFs used for?

Answer 21

Improving WBC counts after anticancer drugs. However, cannot be used in the case of leukaemia due to abnormal proliferation of WBCs so would run the risk of increasing production of WBCs.

Question 22

How to measure cells per volume in blood counts.

Answer 22

Counted by machine or manually (e.g. RBCs/neutrophils per litre of blood).

Question 23

How do you measure a haematocrit (packed cell volume)?

Answer 23

Centrifuge blood down and the percentage this gives is the percentage that is RBCs.

Question 24

How to measure haemoglobin in the blood?

Answer 24

Use spectroscopy, amount (g) per 1dL or 100ml (or can do per 1L) of blood. Used to identify anaemias.

Question 25

What is the mean corpuscular volume (MCV) and how to you find it?

Answer 25

The volume (fl) of individual RBCs. Work out using:
(Haematocrit) over (RBC per litre). Take the haematocrit as a fraction, so if 45%, use 0.45.

Question 26

What is the mean corpuscular volume (MCV) useful for?

Answer 26

Identifying certain diseases, such as microcytic anaemia (smaller than normal) and macrocytic anaemia (larger than normal). Being macrocytic on its own can indicate alcohol abuse in the past 2-3 months.

Question 27

What does Hb/RBC give?

Answer 27

The mean corpuscular Hb.

Question 28

What does Hb/PCV give?

Answer 28

The mean corpuscular Hb concentration.

Question 29

What does -philia (aka -cytosis) mean?

Answer 29

Increased count- e.g. neutrophilia is increased neutrophil count.

Question 30

What does -penia mean?

Answer 30

Decreased count- e.g. neutropenia means decreased neutrophil count, pancytopenia means a reduction in all cell counts.

Question 31

What is atopy?

Answer 31

Eczema, asthma and hay fever.

Question 32

What are signs of infection?

Answer 32

Significant elevation of WBCs or CRP (C-reactive protein) levels. Chills, nausea, vomiting and confusion are also signs of infection.

Question 33

What are blood groups determined by?

Answer 33

Antigens on RBCs- antibodies to other antigens may be in the plasma.

Question 34

What blood groups to use in transfusions?

Answer 34

Always cross match when giving blood transfusions, but in emergencies use O Rh -ve as it is the unviersal donor. Complications occur in acute haemolytic transfusion reactions.

Question 35

What antigens and antibodies does blood group A have?

Answer 35

a-antigens and b-antibodies.

Question 36

What antigens and antibodies does blood group B have?

Answer 36

b-antigens and a-antibodies.

Question 37

What antigens does blood group AB have?

Answer 37

AB antigens.

Question 38

What antigens and antibodies does blood group O have?

Answer 38

No antigens, but has a- and b-antibodies.

Question 39

Why are Rhesus D (RhD) antigens important?

Answer 39

In pregnancy, if a Rh-ve mothers first child is Rh+ve, but if miscarries or delivers the first child, the mother will produce D antibodies which will fight a 2nd pregnancy- haemolytic disease. Prevent with Anti-D immunisation, which binds to infant cells preventing the raising of antibodies.