Blood Disorders

Question 1

What is polycythemia?

Answer 1

• also known as erythrocytosis
• too many RBCs

Question 2

What is anaemia?

Answer 2

Too little RBCs

Question 3

What is Leukocytosis?

Answer 3

• too many WBCs

Question 4

What is Leukopenia?

Answer 4

• too few WBCs

Question 5

What is thrombocytosis?

Answer 5

• too many platelets

Question 6

What is Thrombocytopenia?

Answer 6

• too few platelets

Question 7

What is Pancytopenia?

Answer 7

• too few RBCs, WBCs and platelets

Question 8

What are the possible causes of Polycythaemia?

Answer 8

Primary:
1. polycythaemia rubra vera (myoproliferative disorder)

Secondary:
2. hypoxia (e.g. living at high altitudes, chronic lung disease)
3. erythropoietin-producing tumours

Relative:
4. dehydration => apparent rise in RBC due to drop in blood plasma

Question 9

What are the effects of Polycythaemia?

Answer 9

• tiredness
  -CNS disturbances: headache, disturbed vision
• bruising
• clotting, sludging (RBC massed along vessel walls => decrease in lumen size & blood flow rate)
• gout

Question 10

Name the causes of Anaemia?

Answer 10

1. Decreased RBC production
- deficiency in
1. Iron => hypochromic (less Hb), microcytic (smaller RBC)
2. vit B12 => megaloblastic (bigger RBC), RBC cannot exit bone marrow

2. Loss of RBC
- due to bleeding

3. Increased destruction of RBC
- haemolysis (RBC lysis)
-> due to membrane defects (e.g. spherocytosis)
-> Hb defects (e.g. sickle cell disease, thalassaemia)
-> enzyme defects (e.g. G6PD deficiency)
- hypersplenism: splenomegaly, splenic sequestration of RBC

Question 11

What causes decreased RBC pdn?

Answer 11

1. Iron => hypochromic (less Hb), microcytic (smaller RBC)
2. vit B12 => megaloblastic (bigger RBC), RBC cannot exit bone marrow

Question 12

What can cause the increased destruction of RBCs?

Answer 12

Haemolysis (RBC lysis) due to:
1. Membrane defects (e.g. spherocytosis)
2. Hb defects (e.g. sickle cell disease, thalassaemia)
3. Enzyme defects (e.g. G6PD deficiency)

Hypersplenism (overactive spleen) due to:
Splenomegaly => causes splenic sequestration of RBC

Question 13

What are the effects of Anaemia?

Answer 13

• Weakness, lethargy
• Dizziness, syncope (fainting)
• Shortness of breath
• Palpitations, chest pain, heart failure
• Pallor (unhealthy pale appearance)

Question 14

How is leukemia clinically classified?

Answer 14

Acute vs Chronic

Question 15

Where do Leukaemias originate from?

Answer 15

Bone marrow
- malignancy of haemopoietic system
- usually large no. of tumour cells circulating in peripheral blood
- does not form masses (unlike lymphomas which arise as discrete tumour masses)

Question 16

The 2 types of leukaemia are? (Based on cells affected)

Answer 16

1. Lymphoid:
   - lymphoid cells give rise to B & T lymphocytes & NK
2. Myeloid: all cells (RBC, granulocytes, monocytes & platelets + lymphocytes)