White Cells

Question 1

what are the three different types of granulocytes?

Answer 1

• basophil
• neutrophil
• eosinophil

Question 2

where do granulocytes originate from

Answer 2

HSC → myeloid precursor → myeloblast → granulocytes

Question 3

why do granulocytes have granules?

Answer 3

contain agents/proteins essential for their microbial function

e. g.
- neutrophils - enzymes to kill bacteria
- eosinophils - toxins to defend agains parasitic infections
- basophils - histamines + heparin (naturally occurring anticoagulant) + proteolytic enzymes (tissue breakdown)

Question 4

what is the growth factor which encourage production/controls of granulocytes?

Answer 4

G-CSF (granulocyte colony-stimulating factor)

Question 5

what is the growth factor which encourage/controls production of macrophages?

Answer 5

M-CSF

-causes neutrophil then macrophage production

Question 6

what is the growth factor which encourage production/controls of granulocyte + macrophages?

Answer 6

GM-CSF

Question 7

when would these growth factors be produced in increase amounts?

Answer 7

e. g.
- inflammation
- infection

Question 8

how does a granulocyte mature?

Answer 8

myeloblast → divides into two myelocytes → nucleus becomes band/indented → neutrophil

overall: size gets smaller + development of granules

Question 9

what dye do basophils take up?

Answer 9

basic (hence name)

Question 10

what dye do eosinophils take up?

Answer 10

eosin

Question 11

what dye do neutrophil take up?

Answer 11

basic + acidic dye in basic way

Question 12

what is the main function of the neutrophil?

Answer 12

-defence agains infection through phagocytosis (mainly in tissues)

Question 13

how do neutrophils work physiologically?

Answer 13

1) chemotaxis (cytokine attracts neutrophils)
2) adhesion + margination (to endothelium)
3) rolling along endothelium
4) diapedesis as they come out through the capillary wall
5) migration + phagocytosis of bacteria = kill bacteria or break down tissue

Question 14

what is the main function of eosinophils?

Answer 14

defence against parasitic infections

spend even less time in the circulation than neutrophils

Question 15

what is the main function of basophils?

Answer 15

involved in variety of immune and inflammatory responses

Question 16

where do monocytes originate from?

Answer 16

HSC → myeloid stem cell → monoblast (myeloblast) → monocyte

Question 17

what is the main function of monocytes?

Answer 17

-ingesting bacteria and present the broken down bacteria antigen on surface to lymphoid cells which will respond to the antigenic stimulus

Question 18

what happens when they migrate into tissues?

Answer 18

-develop into macrophages

Question 19

what are the key features of macrophages?

Answer 19

• largest of the granulocytes
• nuclei of erythroblasts inside
• bacteria inside macrophages

Question 20

what are the functions of macrophages?

Answer 20

• scaveging functions

- store + release iron when they ingest old RBCs (ferritin + hemosiderin - storage forms of iron)

Question 21

what is the origin of lymphocytes?

Answer 21

HSC → lymphoid stem cells → NK cells / small lymphocytes → B + T cells

Question 22

what cells can b-lymphocytes mature into?

Answer 22

plasma cells (bigger than small lymphocytes, large Golgi zone where antibodies produced) → antibodies

Question 23

which immunity are t-lymphocytes involved?

Answer 23

cell-mediated immunity

Question 24

which immunity are NK cells involved?

Answer 24

innate → kill tumour cells + virus infected cells

Question 25

What are the 2 main types of abnormalities that can occur in white cells?

Answer 25

-changes can be numerical, morphological or both 1. leucocytosis (too many white cells e.g. neutrophilia) 2. leucopenia (reduction in wbcs e.g. neutropenia)

Question 26

Reasons for neutrophilia (too many neutrophils)?

Answer 26

1) infection 2) inflammation 3) infarction/tissue damage 4) myeloidproliferatuve neoplasm 5) pregnancy 6) exercise 7) after corticosteroids neutrophilia + left shift connected non-segmented nucleuses

Question 27

Reasons for neutropenia (too few neutrophils)?

Answer 27

1) chemotherapy + radiotherapy (as targets bone marrow) 2) autoimmune disorders 3) severe bacterial infections (strong pull so all neutrophils leaving bloodstream into tissues and BM can't keep up) 4) viral infections 5) drugs

Question 28

What happens to patients with very low neutrophil counts (< 0.5 × 109/l)?

Answer 28

high risk of serious infection e.g. sepsis

Question 29

What is the name of a morphological abnormality a neutrophil could have?

Answer 29

neutrophil hypersegmentation | when there is an incr. in average number of neutrophil lobes

Question 30

Reasons for Neutrophil hypersegmentation?

Answer 30

due to b12, folate deficiency

Question 31

Reasons for Lymphocytosis (too many lymphocytes)?

Answer 31

1) viral infection 2) leukaemia 3) sometimes bacterial infections e.g. pertussis

Question 32

Definition of lymphomenia and what type of cells it mainly consists of?

Answer 32

total lymphocyte count as less than 1x10^9/l

Question 33

Reasons for Lymphopenia (too few lymphocytes)?

Answer 33

1) HIV 2) chemotherapy 3) radiotherapy 4) corticosteroids 5) severe infection

Question 34

Reasons for Monocytosis (too many monocytes)?

Answer 34

1) infection (chronic) 2) chronic inflammation 3) some leukaemia

Question 35

Reasons for Eosinophilia (too many eosinophils)?

Answer 35

1) allergy e.g. asthma 2) parasitic infection 3) leukaemia

Question 36

Reasons for Basophilia (too many basophils)?

Answer 36

uncommon 1) leukaemia or related conditions

Question 37

Summary: Transient leucocytosis is frequently associated with?

Answer 37

associated with infection bacterial: neutrophilia / monocytosis viral: lymphocytosis parasitic: eosinophilia

Question 38

Summary: Persistent leucocytosis may be caused by?

Answer 38

leukaemia