University of Houston - CHAP 23

1)Which of the following cells is most likely to be killed via the alternative complement pathway?

Choose one:

1. A virally infected host cell
2. A Gram-negative bacterium
3. A Gram-positive bacterium
4. A parasitic worm

2. Some cells of the innate immune system present antigens to T cells of the adaptive immune system. Cells that can present the antigens are logically called antigen-presenting cells (APCs) and include which of the following? Choose one or more:

A.natural killer cells

B..dendritic cells D.macrophages

E.eosinophils

F.neutrophils

3. Which of the following complement pathways is activated by lipopolysaccharide?

Choose one:

1. alternative complement pathway
2. classical complement pathway
3. lectin pathway
4. opsonin pathway

4. A Streptococcus pneumoniae mutant does not produce a capsule. What will be the most likely result of this mutation if the bacteria infect a host?

Choose one:

1. Without the capsule, the bacteria are more likely to cause septicemia (an infection of the blood) because they will enter the blood by extravasation more easily than encapsulated bacteria.
2. Without the capsule, opsonization of the mutant will not be required for host macrophages to ingest the microbe, making it less pathogenic.
3. Without the capsule, the bacteria no longer produce MAMPs and so will escape detection by the host's immune system.
4. The loss of the capsule will protect the bacteria from the oxidative burst in the phagolysosome and allow them to survive within phagocytes.

5. Pyrogens indirectly cause the hypothalamus to Choose one:

1. alter the temperature set point erratically and frequently.
2. keep the temperature set point the same.
3. decrease the temperature set point.
4. increase the temperature set point.

6. Which receptors on host cells participating in innate immunity recognize bacterial proteins?

Choose one:

1. CD47 receptors
2. MHC receptors
3. Fc receptors
4. Toll-like receptors

7. Which receptors on host cells participating in innate immunity recognize bacterial proteins?

Choose one:

1. CD47 receptors
2. MHC receptors

3. Fc receptors
4. Toll-like receptors

8. The gut microbiome benefits the host in many ways. One benefit of the gut microbiome is that it helps to prevent infection by pathogenic microbes. To directly compete with and inhibit the growth of pathogenic microbes, members of the gut microbiome do which of the following?

Choose one or more: A.synthesize vitamins

2. degrade complex carbohydrates
3. degrade mucin
4. compete for mates
5. compete for nutrients
6. occupy attachment receptors
7. secrete substances that inhibit the growth of pathogens

9. Which of the following locations is LEAST likely to harbor commensal microbes?

Choose one:

1. Vagina
2. Blood
3. Skin
4. Mouth

10. How does the alternative complement pathway kill the invading microbial cell?

Choose one:

1. It enhances the phagocytosis of the microbes by host cells.
2. It destroys the proton motive force required for energy production.
3. It causes the oxidation of the microbe's membranes by producing superoxide ion.
4. It stimulates the production of neutrophil extracellular traps (NETs), which trap the microbes and kill them with antimicrobial compounds.

11. Which of the following is not true of the immune system?

Choose one:

1. Its cells differentiate between self and nonself.
2. Its two branches, innate and adaptive, are isolated from each other.
3. It includes organs, cells, and cell products.
4. It is capable of responding to almost any foreign molecule.

12. Which of the following chemical defenses are produced by host cells to destroy invaders’ membranes?

Choose one:

1. Lysozyme
2. Defensins
3. Acidic pH
4. Superoxides

13. What is the most likely mechanism the infected macrophages will use to combat the invading bacteria?

Choose one:

1. autophagy
2. extravasation
3. opsonization
4. degranulation

14. The five classic signs of localized inflammation are redness, warmth, pain, swelling, and altered function at the affected site. Altered function is caused when swelling interferes with the movement and function of the inflamed area. The other signs are matched with their causes below. Which sign and cause are mismatched?

Choose one:

1. pain – increased production of prostaglandin
2. redness – increased blood flow to the site

C.warmth – increased production of pyrogens

D.swelling – increased vascular permeability

15. Which of the following is true of the normal intestinal microbiota?

Choose one:

1. The normal microbiota contains only bacterial species.
2. There are up to two dozen different species present.
3. The microbes that are present will not harm the host if they colonize a different tissue.
4. It can help aid digestion and absorption of nutrients.

16. Interferons are cytokines produced by host cells in response to intracellular infection. There are two types of interferons, type I and type II. Which of the following is a difference between these two types?

Choose one:

1. Type I includes interferon-alpha and interferon-beta, while type II includes interferon-omega.
2. Type I interferes with viral replication, while type II activates white blood cells.
3. Type I is part of innate, nonspecific immunity, while type II is part of adaptive, specific immunity.
4. Type I binds to extracellular pathogens, while type II binds to intracellular pathogens.

17. Cases of pseudomembranous enterocolitis have been cured with fecal transplants in which the gut microbiome of a donor healthy person is transferred into the patient. Fecal transplants work to cure this resistant infection because

Choose one:

1. the  donor's  healthy  microbiome  outcompetes  the  C. difficile and restores balance to the gut microbiome in the patient.
2. inflammation that combats the C. difficile infection is promoted in the gut of the patient by the donor's microbiome.
3. C. difficile is sensitized to antibiotic drugs by factors in the donor's microbiome.
4. a different strain of C. difficile from the healthy donor replaces the patient's strain.

18. Which complement cascade pathway depends on the production of antibodies?

Choose one:

1. The classical pathway
2. The CD47 pathway
3. The lectin pathway
4. The alternative pathway

19. Extravasation of immune cells depends on Choose one:

1. down regulation of selectin proteins on endothelial cells.
2. increased permeability of endothelial cell junctions.
3. increased vasoconstriction.
4. antibody production by B cells.

20. Which of the following host cell products prevents viral infections by inhibiting viral replication?

Choose one:

1. NOD-like receptors
2. Toll-like receptors
3. type II interferons
4. type I interferons

21. Which of the following is a physical barrier to microbial infection in innate immunity?

Choose one:

1. Acidic pH
2. Tightly linked epithelial cells
3. Antimicrobial peptides
4. Superoxide radicals

22. These two statements are examples of the connections between which of the following?

Choose one:

1. neutrophil extracellular traps (NETs) and the disease lupus
2. phagocytosis and inflammation
3. primary and secondary lymphoid tissues
4. innate and adaptive branches of immunity

23.  Type I interferons Choose one:

1. are not host species specific (e.g., rabbit interferon will work in mice).
2. are produced in response to extracellular pathogens.
3. help protect cells from viral infection.
4. reduce cellular levels of double-stranded RNA endonucleases.

24. Bradykinin plays several roles in inflammation. According to the figure, which of the following is not a function of bradykinin in inflammation?

Choose one:

1. causing capillary cells to release prostaglandins
2. stimulating the release of cytokines by macrophages
3. triggering the release of histamine from mast cells
4. loosening the junctions between endothelial cells

25. extravasation of neutrophils and also results in the edema of inflammation. Finally, it triggers capillaries to release prostaglandins, which bind to neurons, causing the pain of inflammation.

Microbial species of the microbiota may interfere with colonization of pathogens by all EXCEPT which of the following mechanisms?

Choose one:

1. Phagocytosis
2. Through the synthesis of antimicrobial compounds
3. Competition for food sources
4. Competition for attachment receptors on host cells

26. Moderate fever can actually be beneficial because it Choose one:

A. moves the temperature outside the pathogens’ optimal range.

3. increases inflammation.
4. causes enzymatic denaturation.
5. increases iron availability to pathogens.

27. Which of the following activates a natural killer (NK) cell to kill a host cell?

Choose one or more:

1. absence of MHC I on the NK cell
2. presence of antibodies on the host cell
3. absence of MHC I on the host cell
4. presence of MHC I on the NK cell
5. absence of antibodies on the NK cell
6. presence of antibodies on the NK cell
7. presence of MHC I on the host cell
8. absence of antibodies on the host cell

28. The microbiome has both associated benefits and risks. What are some of the risks associated with the oral microbiome?

Choose one or more:

1. tooth decay

B. subacute bacterial endocarditis C.bacteremia

D.urinary tract infections

E.gastric ulcers

29. How does a moderate fever slow bacterial growth?

Choose one:

1. produces suboptimal temperatures for the microbe
2. increases iron availability
3. produces prostaglandin E2
4. produces pyrogens, which opsonize microbes

30. In which of the following body sites would the mere presence of microbes indicate an infection?

Choose one:

1. stomach
2. blood
3. bladder
4. skin
5. lungs