Lecture 8- Haematology 1

Question 1

Homolytic disease of the newborn.

1. When can it happen?
2. How does the mother react to a sensitizing event?
3. If the blood then mixed what would happen to the baby?

Answer 1

1. When the mother is rhesus negative and the foetus is rhesus positive. The baby has inherited the D antigen from the dad.
2. The blood mixes in a sensitizing event. SO the mother now makes anti-D antibodies which circulate in her blood.
3. The antibodies enter the baby, stick to the antigen and break it down. It will clump and cause organ failure.

Question 2

What is anaemia?

Answer 2

A haemoglobin concentration in whole blood below the accepted range

Question 3

What are the approx levels of haemoglobin that indicate anaemia in men and women?

Answer 3

1. Men- below 13.5g /dL
2. Women- below 12.0g /dL

Question 4

What are the 3 types of anaemia and their causes?

Answer 4

1. Iron deficiency- pregancy
2. Megaloblastic anaemia- deficiency in vitamin B12, Intrinsic factor (enables b12 absorption) and folic acid deficiency. RBCs don’t divide properly.
3. Sickle cell- genetic. abnormal RBC structure

Question 5

Where does erythropoeisis occur?

1. In the foetus
2. In infants
3. In adults

Answer 5

1. Yolk sac, liver and spleen.
2. All bone marrow (all red at this point)
3. Only red bone marrow (has differentiated to yellow and red)

Question 6

What is the rate of RBC production?

Answer 6

2-3 million RBCs per second

Question 7

What’s the composition of the blood?

Answer 7

55% Plasma

45% RBCs

>1% WBCs and platelets

Question 8

What are the 5 requirements for erythropoeisis?

Answer 8

1. Iron
2. Vitamin B12
3. Folic acid- for maturation of RBC
4. Intrinsic factor- for absorption of B12
5. Amino acids

Question 9

What are the stages in the cycle of a RBC?

Answer 9

1. Erythropoeisis
2. Rbc in circulation
3. Aged or damaged cell
4. Goes to liver or spleen
5. Macrophages break it down to Iron and Bilirubin
6. BIlirubin goes to liver and secreted into bile, then urine or poo
7. Iron and amino acids recycled

Question 10

What are the parts of haemoglobin?

Answer 10

• Tetramer of 2 alpha and 2 beta subunits
• Each subunit is 1 haem group with an FE2+ in centre. Attacked to a long chain of globin