19. Innate Immunity

Where are bacteria killed by enzymes and toxic substances once ingested by a white blood cell?

Which of the following statements about phagosomes and phagolysosomes are true?

Which of the following statements about phagocytosis is incorrect?

Some pathogens create C5a peptidase, an enzyme that destroys C5a proteins. Which of the following is not a benefit that the pathogen would experience after destroying C5a proteins?

DRAW IT Label on the figure the following processes that result in phagocytosis: margination, diapedesis, adherence, and phagolysosome formation.

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Patients with X-linked chronic granulomatous disease are susceptible to infections because their neutrophils don’t generate an oxidative burst. What is the relation of the oxidative burst to infection?

Legionella uses C3b receptors to enter monocytes. This

a. prevents phagocytosis.

b. degrades complement.

c. inactivates complement.

d. prevents inflammation.

e. prevents cytolysis.

Chlamydia can prevent the formation of phagolysosomes and therefore can

a. avoid being phagocytized.

b. avoid destruction by complement.

c. prevent adherence.

d. avoid being digested.

e. none of the above

If the following are placed in the order of occurrence, which would be the third step?

a. diapedesis

b. digestion

c. formation of a phagosome

d. formation of a phagolysosome

e. margination

In 1884, Elie Metchnikoff observed cells collected around a splinter inserted in a sea star embryo. This was the discovery of

a. blood cells.

b. sea stars.

c. phagocytosis.

d. immunity.

e. none of the above

Which of the following does not stimulate phagocytes?

a. cytokines

b. IFN-y

c. C3b

d. lipid A

e. histamine

Indicate which statements are true. Correct all false statements by changing the underlined words.

__________ Wandering macrophages experience diapedesis.

Indicate which statements are true. Correct all false statements by changing the underlined words.

__________ In phagocytosis, adhesion involves the binding between complementary chemicals on a phagocyte and on the membrane of a body cell.

Label the steps of phagocytosis.

a. ________

b. ________

c. ________

d. ________

e. ________

f. ________

Indicate which statements are true. Correct all false statements by changing the underlined words.

__________ Opsonization occurs when a phagocyte’s pseudopods surround a microbe and fuse to form a sac.