Granulopoiesis

Question 1

when and where does granulopoiesis occur

Answer 1

bone marrow after 4-5 months gestation

Question 2

what is granulopoiesis?

Answer 2

the maturation of myeloblast to granulocyte which takes 6-10 days

Question 3

what are the granulocytes?

Answer 3

neutrophils, eosinophils, basophils

Question 4

what is the reference range for neutrophils?

Answer 4

2-7 x10>9 /L

Question 5

what enzymes do neutrophils contain?

Answer 5

myeloperoxidase, alkaline phosphatase, acid phosphatase, hydrolase, lactoferrin and lysozyme

Question 6

where do neutrophils get energy?

Answer 6

ATP from glycolysis

Question 7

what is the function of neutrophills?

Answer 7

kill bacteria and some fungi

Question 8

what are the steps in neutrophils killing bacteria?

Answer 8

1. chemotaxis
2. opsonisation
3. phagocytosis
4. killing

Question 9

what is opsonisation?

Answer 9

bacteria surface modified, immune adherance - bacteria bound to neutrophil membrane

Question 10

what is chemotaxis?

Answer 10

chemotaxins (proteins derived from plasma protein pathways) direct neutrophils to site of infection

Question 11

how do neutrophils phagocytose bacteria?

Answer 11

enclose in phagocytotic vacuole into which granules are discharged

Question 12

what are the stages in bacteria killing?

Answer 12

1. oxygen dependent: myeloperoxidase, hydrogen peroxide, superoxide, hydroxyl radical formation
2. oxygen independent; fall in pH, lyzozyme attach cell wall, cationic proteins

Question 13

when are primary granules formed?

Answer 13

promyelocyte stage

Question 14

what do primary granules contain?

Answer 14

Myeloperoxidase
Bacterial permeability inducing factor
Lysozyme
Elastase
Acid hydrolases

Question 15

what does myeloperoxidase do?

Answer 15

non specific converts h202 to hypochlorus acid which has antimicrobial properties

Question 16

what does bacterial permeability inducing factor do?

Answer 16

binds to LPS (targets gram neg) to increase membrane permeability

Question 17

what does lysozyme do?

Answer 17

degrades bacterial cell wall

Question 18

what does elastase do?

Answer 18

targets gram neg, fungi and enterotoxins

Question 19

what do the secondary granules provide?

Answer 19

the distinctive staining patterns that are used in the identification of granulocytes and their precursors

Question 20

what do the secondary granules contain?

Answer 20

Lactoferrin which has bacteriostatic and bactericidal

Lysozyme is also found in the secondary granules as well as the primary granule

Question 21

what do the Tertiary granules include?

Answer 21

gelatinase which is capable of digesting denatured collagen as well as intact collagen

Question 22

what does digestion by gelatinase allow?

Answer 22

neutrophils to migrate through the blood vessels basement membrane and enter tissue fluid