Deck 4: Infection and Immunity: Hostparasite Relationships

Question 1

Which of the following can function as chemotactic agents?

A)Complement fragments
B)Bacterial products
C)Cytokines produced by white blood cells responding to an inflammatory site
D)Mediators released from damaged tissue
E)All of the above

Answer 1

All of the above

Question 2

Which of the following defines commensalism?

A)Biologic relationship between two organisms in which one benefits and the other is harmed.
B)Biologic relationship between two organisms in which both are harmed.
C)Biologic relationship between two organisms in which both benefit.
D)Biologic relationship between two organisms in which one benefits and the other remains unharmed.

Answer 2

Biologic relationship between two organisms in which one benefits and the other remains unharmed.

Question 3

Which organism below is easily phagocytized but is capable of surviving and multiplying intracellularly?

A)Staphylococcus aureus
B)Streptococcus pyogenes
C)Hemophilus influenzae
D)Chlamydia
E)Streptococcus pneumoniae

Answer 3

Chlamydia

Question 4

Normal microbial skin flora is primarily concentrated on the

A)dry areas of skin with heavy hair.
B)moist areas of skin near sweat glands.
C)dry areas of skin with light hair.
D)fingernails and toenails.

Question 5

Which of the following are mechanisms by which microbes evade phagocytosis?

A)Produce collagenase
B)Produce leukocidins
C)Produce hyaluronidases
D)Motility

Question 6

Phagocytes are most effective against

A)protozoan parasites.
B)extracellular bacteria.
C)intracellular viruses.
D)Phagocytes are equally effective against all the microbes listed.
E)intracellular bacteria.

Question 7

Which microbial product below helps Staphylococcus aureus create a protective fibrin wall around itself?

A)Fimbrae
B)Capsule
C)Coagulase
D)Hyaluronidase
E)Hemolysins

Question 8

Microbes that colonize a particular person for a long period of time are called

A)nonpathogenic microbial flora.
B)usual microbial flora.
C)transient microbial flora.
D)resident microbial flora.

Question 9

A microorganism that typically does not cause disease in a normal host but that does cause disease if the host is compromised in some way is called

A)symbiotic.
B)commensal.
C)opportunistic.
D)parasitic.
E)pathogenic.

Question 10

Which microbial product below helps organisms penetrate tissues?

A)Hemolysins
B)Hyaluronidase
C)Capsule
D)Fimbrae
E)Coagulase

Question 11

Release of inflammatory mediators causes increased vascular permeability. Which of the four hallmarks of inflammation does this cause?

A)Heat
B)Erythema
C)Pus
D)Pain
E)Edema

Question 12

Quantitatively, the most important defense against food- borne pathogens in the gastrointestinal tract is

A)peristaltic movement.
B)ciliated cells.
C)mucus cells.
D)resident phagocytic cells.
E)low pH and high enzymatic content of the stomach.

Question 13

What is the collective purpose of nasal hair, mucus secretions in the naspopharyngeal tract, phagocytic cells in the throat, bronchial lysozyme, sneezing, and coughing?

A)To keep organisms from entering the lower respiratory tract and causing infection.
B)To keep normal flora in the oropharynx from entering the eustachian tube causing infection.
C)To keep normal flora in the oropharynx from causing infection.
D)To maintain a sterile environment in the oropharynx.

Question 14

Which organism below produces a protein called Protein A that binds to the Fc portion of IgG?

A)Chlamydia
B)Hemophilus influenzae
C)Streptococcus pyogenes
D)Streptococcus pneumoniae
E)Staphylococcus aureus

Question 15

All of the following organisms are virulent at least in part due to exotoxins they secrete except

A)Staphylococcus aureus
B)Mycobacterium tuberculosis
C)Streptococcus pyogenes
D)Corynebacterium diphtheriae
E)Clostridium botulinum

Question 16

The microbial structures that promote attachment of the microbe to tissues, making phagocytosis more difficult, are

A)Panton- Valentines.
B)fimbrae.
C)cell walls.
D)capsules.
E)flagella.

Question 17

Which of the following situation(s)represents an event that could result in an opportunistic infection?

A)Subject is stabbed with a knife.
B)Subject has dental surgery.
C)Subject has leukemia.
D)Subject is undergoing radiation for cancer treatment.
E)All of the above.

Question 18

A microorganism that consistently causes disease in normal people with competent immune systems is a

A)virulent pathogen.
B)opportunistic pathogen.
C)commensal pathogen.
D)true pathogen.
E)symbiotic pathogen.

Question 19

Each body site below is paired correctly with an expected component of the normal microbial flora except

A)colon/enterobacteriaceae.
B)vagina/lactobacilli.
C)upper respiratory tract/viridians streptococci and diphtheroids.
D)skin/Staph epidermis and Propionibacterium.
E)All of the above are paired correctly.

Question 20

Which of the following antimicrobial substance is(are)secreted by mucous membranes?

A)Lactoferrin
B)Lysozyme
C)Antibodies
D)All of the above

Question 21

List ways in which the skin resists the penetration of microorganisms.

Question 22

Which organism below evades the adaptive immune response by antigenic variation?

A)Borrelia recurrentis
B)Plasmodium vivax
C)Brucella abortis
D)Listeria monocytogenes
E)Mycobacterium tuberculosis

Question 23

Normal microbial flora never cause disease in immunocompetent hosts.

Question 24

When an infection occurs in a fetus or early in the life of the neonate, the immune response may be inadequate due to

A)the induction of tolerance.
B)suppression of the immune system.
C)interference from maternal T cells.
D)antigenic variation.

Question 25

A particular microorganism may be commensal in one body site but parasitic in another body site.

Question 26

Discuss the benefits of normal microbial flora for the host.

Question 27

Differentiate virulence and pathogenicity.

Question 28

What do infections with HIV, cytomegalovirus, and Epstein- Barr virus all have in common?

A)Evasion of the immune system by antigenic variation.
B)An induction of immune tolerance to other viruses.
C)Poor production of antibody by the host.
D)Immunosuppression of the host.

Question 29

Once an organism is engulfed by macrophage, it is always digested and killed.

Question 30

Some organisms evade the immune response by changing the antigens expressed on their surface during the course of an infection.

Question 31

No microorganism is capable of directly penetrating keratinized, intact human skin.

Question 32

A human could never harbor a pathogenic microorganism as resident flora.

Question 33

Erythema in an inflamed site is caused by release of inflammatory mediators that increase blood flow to the affected area.

Question 34

Discuss how the nature of a particular body site influences the normal microbial flora located there.

Question 35

An important feature of many pathogenic viruses is their resistance to

A)lysozyme.
B)interferon.
C)interleukin- 2.
D)interleukin- 1.
E)lactoferrin.

Question 36

List ways in which microorganisms evade phagocytosis.

Question 37

A Boy Scout goes camping in the woods for a week and doesn't take a shower. When he gets home, the microbes that he carried all week long are washed away in the shower, never to return. The microbes that the boy acquired in the woods and carried all week would be called transient microbial flora.

Question 38

People with immune systems suppressed by HIV are more susceptible to viral, fungal, and protozoal infections.

Question 39

Which organism below evades the adaptive immune response by surviving inside host liver cells?

A)Mycobacterium tuberculosis
B)Borrelia recurrentis
C)Listeria monocytogenes
D)Plasmodium vivax
E)Brucella abortis

Question 40

The movement of white blood cells through blood vessel walls is called chemotaxis.

Question 41

The causative organism of botulism is particularly virulent because of the it secretes.

Question 42

Microorganisms that are consistently associated with human disease are called .

Question 43

Microorganisms with capsules are better able to evade by neutrophils and monocytes.

Question 44

Antibiotic associated colitis has been associated with the organism .

Question 45

Microbes that have very low infective doses and/or that are very harmful to the host are very .