Haematology

Question 1

Define Landsteiner’s Law

Answer 1

Whenever an antigen (A and/ or B) is not present on red cells, the corresponding antibody is found in the serum

Question 2

Describe the ABO blood group

Answer 2

ABO gene locus is on chromosome 9
Gene product is an enzyme- A/B transferase
Requires H antigen to action

Question 3

Which ABO blood group gene is recessive?

Answer 3

O

Question 4

Describe ABO blood group antibodies

Answer 4

Produced in response to common chemical structures in the environment
Not present at birth, detectable from 4 months old
Strength can vary due to age/ health

Question 5

List the antibodies and the blood group’s that produce them

Answer 5

Anti A- B
Anti B- A
Anti A,B- O, single antibody, not a mixture

Question 6

Which antigens and bodies does group A have?

Answer 6

Antigen- A
Antibodies- Anti-B

Question 7

Which antigens and bodies does group B have?

Answer 7

Antigens- B
Antibodies- Anti-A

Question 8

Which antigens and bodies does group O have?

Answer 8

Antigens- None (H)
Antibodies- Anti- A,B

Question 9

Which antigens and bodies does group AB have?

Answer 9

Antigens- A & B
Antibodies- none

Question 10

Describe the Rh blood group system

Answer 10

One of the most complex multi- allelic blood group systems
56 antigens identified
5 main= D, C E, c, e
Rh gene locus is on C-some 1
2 genes involved- RHD & RHCE
Only present on cell membrane id RhAG protein is present

Question 11

What happens when RHD and RHCE are inherited together?

Answer 11

Known as haploytype because genes are co-dominant
Results in 8 possible phenotypes

Question 12

List and define the 7 terms used to describe red cell shape and size

Answer 12

Microcyte- Small
Macrocyte- Large
Poikilocytosis- Variation is shape
Anisocytosis- Varation in size
Hyper/ hypochromic- Inc/ dec colour
Dimorphic- 2 distinct populations
Polychromasia- Variation in colour

Question 13

What are neutrophils?

Answer 13

Most numerous number of WBC in normal peripheral blood
Multi- lobed nucleus
Stains dark purple
Granular cytoplasm- stains light blue
Granules contain enzyme/ antibacterial substances
Most important phagocytotic cell
Engulfs toxins, viruses and foreign cells

Question 14

What are monocytes?

Answer 14

Largest WBC
Abundant in light blue granular cytoplasm
May have vacuoles
Kidney bean shaped nucleus
Phagocytotic cell= engulfs material
Circulate in peripheral blood
Mature into macrophages
Play a key role in innate immunity

Question 15

What are eosinophils?

Answer 15

Less common in peripheral (1-3%)
Granular cytoplasm- stains pink/ red
Granules contain histamines
Two- lobed nucleus- stain a blue colour

Question 16

What are basophils

Answer 16

Cytoplasmic granules, large obscure nucleus
Uncommon in WBC in peripheral (>1%)
Poorly understood
Contain histamine and heparin= similar function

Question 17

What are lymphocytes

Answer 17

Smallest WBC, marginally larger than RBC
Cytoplasm in a granular, stains pale blue
Nucleus, proportionally large= stains dark blue
2nd most common WBC (20-40%)
Raised numbers indicate viral infection