Neurtrophils and Eosinophils

Question 1

What is the structure of the nucleus of neutrophils?

Answer 1

it is condensed chromatin - segmented

Question 2

What are neutrophils considered in regards to a bacterial infection?

Answer 2

it is the first line of defense

Question 3

How long do neutrophils circulate?

Answer 3

8-10 hours

Question 4

What are neutrophils removed by?

Answer 4

migration into the gut or by Kuepfer cells in the liver

Question 5

How long can neutrophils live in normal tissue?

Answer 5

1-2 days

Question 6

In tissues, how do neutrophils die?

Answer 6

via apoptosis

Question 7

Are neutrophils innate or adaptive?

Answer 7

innate

Question 8

What is the origin of neutrophils?

Answer 8

bone marrow

Question 9

What are the important surface receptors on a neutrophil?

Answer 9

Fc receptors for IgG, C3b receptors, and selectin and integrin (cell adhesion receptors)

Question 10

What is margination?

Answer 10

in post capillary venules, neutrophils loosely bind to endothelium via selectin adhesion molecules and roll along

Question 11

How does the margination pool influence neutrophil counts in blood samples?

Answer 11

it will be lower than the actual number due to the rolling and adhesion

Question 12

What is selectin?

Answer 12

a light binding adhesion molecule

Question 13

What is integrin?

Answer 13

a tight binding adhesion molecule

Question 14

What is diapedisis?

Answer 14

the exiting of netrophils between cells

Question 15

What is chemotaxis?

Answer 15

when neutrophils follow the chemical gradient from a lesser to a higher concentration

Question 16

Define opsonize.

Answer 16

coating and preparing to be eaten

Question 17

Define phagocytosis.

Answer 17

actual process of being eaten by the cell

Question 18

Define phagosome.

Answer 18

membrane bound vesicle made after phagocytosis

Question 19

Define phagolysosome.

Answer 19

when the phagosome fuses with the lysosomes

Question 20

Why is the interaction between opsonized bacteria and neutrophils different than the interaction with bacteria that are not opsonized?

Answer 20

there is no receptor mediated event in non opsinized

Question 21

What are the killing mechanisms of a neutrophil?

Answer 21

lytic enzymes and antimicrobal peptides from granules, oxidative metabolism (respiratory burst), neutrophil extracellular traps (NETs)

Question 22

What are the important molecules involved in the killing mechanisms of neutrophils?

Answer 22

hydrolases, lysozomes, defensins, and myeloperidoxase

Question 23

What is the neutrophils most potent killing mechanism?

Answer 23

the oxidative burst

Question 24

What mechanism do neutrophils use as a last resort that lead to their death?

Answer 24

neutrophil extracellular traps (NETs)

Question 25

What is a defensin?

Answer 25

Small catatonic proteins that kill bacteria by poking a hole in their membrane, especially gram positives

Question 26

Where are defensins located?

Answer 26

in phagocytic cell granules and produced by epithelial cells\

Question 27

What can decrease neutrophil function?

Answer 27

glucocorticoids

Question 28

Why do glucocorticoids decrease neutrophil function?

Answer 28

Inhibit endothelial selectin/integrin expression, Inhibit neutrophil emigration into tissues = decreased chemotaxis, Decrease neutrophil killing ability, Decreased phagocytosis

Question 29

What does long term decrease in neutrophil funciton lead to?

Answer 29

a higher susceptibility to bacterial infections

Question 30

What clinical conditions can stimulate eosinophilic response?

Answer 30

parasitism and allergies

Question 31

How is eosinophilic response enhanced?

Answer 31

IgE