Deck 23: Human Microbiota and Innate Immunity

Question 1

Which structure engulfs microbes by phagocytosis?

A) hair follicle
B) sebaceous gland
C) blood vessels
D) sweat glands
E) subcutaneous tissue

Answer 1

C

Question 2

The microbiome can influence obesity through

A) regulating energy metabolism.
B) increasing intestinal inflammation.
C) creating a more diverse gut microbiome.
D) It does not influence obesity.
E) no bacterial interactions.

Answer 2

A

Question 3

Much of the ________ is normally free from microbes in a healthy individual.

A) nose
B) mouth
C) skin
D) respiratory tract
E) genitourinary tract

Answer 3

E

Question 4

Which of the following is NOT a lymphoid organ?

A) tonsils and adenoids
B) spleen
C) appendix
D) stomach
E) bone marrow

Question 5

Which factor does NOT account for the hygiene hypothesis?

A) exposure to animals
B) caves
C) soap
D) bugs
E) feces

Question 6

Which part of the body does NOT meet the external environment?

A) skin
B) mouth
C) gastrointestinal tract
D) blood
E) genitourinary tract

Question 7

Which of the following types of cells are antigen-presenting cells?

A) only eosinophils
B) platelets and macrophages
C) only macrophages
D) only neutrophils
E) macrophages and dendritic cells

Question 8

Which of the following cell types would most likely be elevated in a viral infection?

A) eosinophils
B) lymphocytes
C) basophils
D) platelets
E) complement

Question 9

Which of the following factors contribute to dysbiosis?

A) emotional stress
B) carbohydrate catabolism
C) probiotics
D) bacteriocin
E) anti-inflammatory cytokines

Question 10

Which of the following would contribute to a compromised immune system?

A) blood pressure medication
B) antidepressant drugs
C) anticancer drugs
D) probiotics
E) vitamins

Question 11

Which condition is NOT related to obesity?

A) diabetes
B) cardiovascular disease
C) cancer
D) nonalcoholic fatty liver disease
E) alcoholism

Question 12

Which part of the genitourinary tract is considered sterile?

A) kidney
B) bladder
C) distal urethra
D) genital tract
E) vagina

Question 13

An organism found on human skin that derives benefit from but does not harm the host is described as a(n)

A) parasite.
B) commensal.
C) opportunist.
D) pathogen.
E) mutualist.

Question 14

The major phagocytic cells in the body are

A) T and B lymphocytes.
B) basophils and eosinophils.
C) erythrocytes and platelets.
D) neutrophils and macrophages.
E) epithelial cells and cilia.

Question 15

Which of the following two organisms are commonly used as probiotics?

A) Streptococcus mutans and Lactobacillus acidophilus
B) Bacteroides and Lactobacillus acidophilus
C) Enterococcus and Enterobacter species
D) Bifidobacterium and Lactobacillus acidophilus
E) Diphtheroids and Fusobacterium species

Question 16

The primary lymphoid organ(s) is/are the

A) adenoids.
B) appendix.
C) Peyer's patches.
D) thymus.
E) tonsils.

Question 17

Which of the following innate immunity mechanisms is mismatched with its associated structure or body fluid?

A) lysozyme-tears
B) mucociliary elevator-intestines
C) highly acidic pH-stomach
D) acidic pH, sebum, salinity-skin
E) low pH-urogenital tract

Question 18

Which of the following is NOT a benefit provided by gut microbiota?

A) inhibits inflammation
B) synthesis of vitamins
C) host tissue development
D) enzymes catalyze food
E) contributes to thin intestinal walls

Question 19

An organism responsible for tooth decay is

A) Pseudomonas aeruginosa.
B) Streptococcus mutans.
C) Neisseria meningitides.
D) Streptococcus pneumoniae.
E) Haemophilus influenzae.

Question 20

Which of the following would NOT result in an increase in natural killer cells?

A) internal parasite
B) herpes virus
C) Neisseria gonorrhoeae
D) bacterial infection
E) cancer

Question 21

All of the following statements are correct regarding defensins EXCEPT that

A) they are produced by skin, GI-tract, and lung cells for defense when stimulated.
B) they form channels that destroy bacterial cytoplasmic membranes, ultimately killing the cell.
C) peptides must bind the negatively charged outer membrane lipopolysacccharides.
D) like antibodies, they are highly specific in pathogen neutralization.
E) variation in defensins produced by different animals partially explains the varying susceptibility of hosts to pathogens.

Question 22

Interferons are

A) high molecular weight cytokines.
B) not species specific.
C) low molecular weight cytokines.
D) not effective against polio virus.
E) not effective against influenza virus.

Question 23

Which part of the physical defense system uses skin-associated lymphoid tissue (SALT)?

A) gastrointestinal tract
B) lungs
C) skin
D) mucus membranes
E) defensins

Question 24

Which of the following creates a channel in target cell membranes?

A) complement
B) defensins
C) natural killer cells
D) complement and defensins
E) complement, defensins, and natural killer cells

Question 25

Lysozymes cause damage to the bacterial

A) cell membrane
B) capsule
C) cell wall
D) DNA
E) ribosomes

Question 26

Interferons are

A) antibacterial agents produced by skin, GI-tract, and lung cells.
B) secreted by eukaryotic cells in response to intracellular infection.
C) only produced by activated phagocytes.
D) host specific and virus specific.
E) able to block bacterial replication.

Question 27

What do NK cells use to distinguish between self and nonself?

A) platelets
B) MHC class I molecules
C) macrophages
D) dendritic cells
E) monocytes

Question 28

Defensins are short cationic peptides that

A) are produced by skin, GI-tract, and lung cells for defense when stimulated.
B) bind to specific protein receptors to gain entry into microbial cells.
C) are only produced by phagocytes upon activation.
D) inhibit microbial DNA synthesis.
E) are equally effective at killing eukaryotic and prokaryotic cells.

Question 29

The figure below shows the ________ pathway.

A) oxidative burst
B) interferon
C) defensins
D) alternative complement
E) complement inflammation

Question 30

A man has been taking excessive amounts of antacids for heartburn. These tablets are very alkaline. Which innate defense mechanism might be altered by his actions?

A) mucociliary elevator
B) lysozyme
C) pH of stomach
D) flushing action of urine
E) skin pH

Question 31

Which of the following is NOT an integral part of the inflammatory process?

A) dilation of blood vessels
B) release of histamines and prostaglandins
C) redness
D) extravasation
E) antibody synthesis

Question 32

Which of the following organisms is NOT a cause of chronic inflammation?

A) a splinter
B) Mycobacterium tuberculosis
C) Mycobacterium marinum
D) Actinomyces bovis
E) biofilms on surgical implants

Question 33

A woman falls and suffers a cut on her leg. The cut went through her skin and she is bleeding. Which of the following defense mechanisms will participate in eliminating microbes contaminating the cut?

A) mucociliary elevator
B) normal skin flora
C) acidic skin secretions
D) lysozyme
E) phagocytosis and the inflammatory response

Question 34

In cystic fibrosis, a mutation has rendered the receptor for binding and inactivating Pseudomonas defective. The affected gene is the CFTR. The CFTR gene product is located in the

A) cytosol.
B) nucleus.
C) plasma membrane.
D) mitochondria.
E) phagosome.

Question 35

Which of the following definitions is mismatched?

A) extravasation-movement of leukocytes through endothelial cells into tissues
B) pus- teeming with white blood cells
C) vasoactive-chemical degradation inside a phagolysosome
D) autophagy-destruction of intracellular pathogens
E) opsonization-formation of pseudopods

Question 36

Which of following is NOT associated with the oxidative burst employed by phagocytic cells to kill bacteria?

A) hydrogen peroxide
B) oxygen radicals
C) NADPH oxidase
D) catalase
E) nitric oxide

Question 37

Which of the following is correct regarding inflammation?

A) The cardinal signs include rash.
B) Some of the phagocytes are stimulated to secrete antibodies specific for the invading pathogen.
C) There is increased blood volume.
D) Differentiation of B cells into plasma cells occurs at the site of infection.
E) AIDS patients have little or no inflammatory responses when they are infected.

Question 38

Which is the correct order of the following events in phagocytosis? (1) discharge of waste material
(2) fusion of the phagosome with a lysosome
(3) adherence of the microbe to phagocytes
(4) digestion of the ingested microbe
(5) formation of a phagosome
(6) ingestion of the microbe by the phagocyte

A) 3, 6, 5, 2, 4, 1
B) 3, 4, 6, 5, 2, 1
C) 6, 5, 2, 4, 3, 1
D) 5, 2, 3, 6, 4, 1
E) 5, 3, 6, 2, 4, 1

Question 39

Opsonization is a process whereby the innate and adaptive immune mechanisms work together

A) to phagocytize an invader.
B) to activate complement proteins.
C) for antibody secretion.
D) to destroy cancer cells.
E) during apoptosis.

Question 40

Extravasation is the process by which ________ move(s) from the bloodstream into surrounding tissues.

A) neutrophils
B) natural killer cells
C) antibodies
D) interferons
E) complement

Question 41

Natural killer cells target ________ cells that ________.

A) infected; have lost MHC class I
B) bacterial; have lost MHC class I
C) bacterial; are coated with complement
D) infected; have lost C-reactive protein
E) infected; secrete cytokines

Question 42

C-reactive protein is an acute-phase reactant that will bind to components of

A) IL-1.
B) TNF-alpha.
C) bacterial cell surfaces.
D) host cell membranes.
E) cytokines.

Question 43

What factors might explain the prevalence of Gram-positive bacteria on human skin's epidermal layer?

Question 44

Interventions that reduce a moderate fever due to infection may be counterproductive because they may

A) produce more pyrogens.
B) produce prostaglandins.
C) induce phagocytosis.
D) slow recovery.
E) dull pain perception.

Question 45

Describe what is happening in the figure below.

Question 46

How is it that Clostrioides difficile, often a part of the normal intestinal microflora, can be the causative agent of pseudomembranous enterocolitis?

Question 47

Which of the following is an example of a semi-specific, innate immune mechanism associated with mucosal surfaces?

A) Secretory IgA prevents adhesion to mucosal surface.
B) Extravasation of neutrophils is triggered by specific signals.
C) Interferons produced by the host will act on specific viruses in the mucosa.
D) Toll-like receptors on the host bind a specific microbe-associated molecular pattern, or MAMP.
E) The type of inflammation mounted varies with pathogen.

Question 48

How does Propionibacterium acnes-an anaerobic Gram-positive normal flora of the skin-cause acne, especially in teenagers?

Question 49

Microbes in and on humans sharpen immunity and protect from infection. Explain why these benefits also come with considerable risk.

Question 50

Which of the following is/are Type I interferon?

A) NOD-receptors
B) TLR4
C) IFN-beta
D) IFN-gamma
E) cytokines

Question 51

The hypothalamus is important because it regulates

A) body temperature.
B) release of complement proteins from the liver.
C) neutrophil phagocytosis.
D) white blood cell differentiation.
E) pain perception.

Question 52

What explains the ability of Helicobacter pylori to defy stomach acidity?

Question 53

How can differences in gut microbiota account for obesity and leanness in humans?

Question 54

The membrane attack complex, or MAC, kills Gram-negative bacteria through

A) opsonization.
B) dissolving the cell wall.
C) the lectin pathway.
D) creating a pore on the bacterial membranes.
E) antibody-dependent cell cytotoxicity, or ADCC.

Question 55

Detection of high levels of mannose-binding lectin in the blood could signify

A) the presence of an invading pathogen.
B) ongoing virus replication.
C) the activation of natural killer cells.
D) high levels of interferons.
E) in-progress differentiation of leukocytes.

Question 56

Toll-like receptors are eukaryotic membrane proteins that bind with bacterial surface molecules and

A) form channels through which bacterial proteins can enter the eukaryotic cell.
B) cause the cell to phagocytize the bacteria.
C) cause the release of antibiotics to kill the bacteria.
D) cause the release of cytokines that trigger host defenses against the bacteria.
E) activate the complement cascade.

Question 57

IFN-gamma protects the host by

A) inducing dsRNA endonucleases.
B) interfering directly with viral replication.
C) having an immunomodulatory role.
D) inducing fever at the hypothalamus.
E) blocking adhesion of pathogens.

Question 58

Why can acne be treated with antibiotics?

Question 59

Using the figure below, demonstrate how butyrate influences appetite.

Question 60

Why are healthy individuals usually "immune" to cholera, whereas malnourished individuals are not?

Question 61

Explain the steps of the basic inflammatory response as pictured in the figure below.

Question 62

How is it that Gram-positive cells are more resistant to complement than Gram-negative cells?

Question 63

Describe how natural killer cells work in response to a bacterial infection.

Question 64

Explain the distinguishing characteristics of innate and adaptive immunity.

Question 65

What is the biology underlying the condition of lupus? How could the symptoms of lupus be lessened on the cellular level?

Question 66

Why is the alternative complement cascade not considered a part of adaptive immunity?

Question 67

Are the Langerhans cells of skin-associated lymphoid tissue (SALT) related to the islets of Langerhans of the pancreas that secrete insulin? What is the function of Langerhans cells?

Question 68

Is it correct to state that bacteria introduced through a skin cut will most likely be engulfed by Langerhans cells?

Question 69

Describe antibody-induced opsonization, the process in which innate and adaptive immunity work together to engulf an invader.

Question 70

Why is it important for people with mitral valve prolapse to take antibiotics prior to a dental exam or procedure?