Exam 4 Flashcards


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1

What is the first line of defense?

Physical and chemical barriers

2

What is the second line of defense?

Inflammation, fever, phagocytosis

3

What are the phagocytes in the 2nd line of defense?

Neutrophils, macrophages

4

What is the 3rd line of defense?

B and T cells

5

What do B cells produce?

Antibodies

6

What is the first step of phagocytosis?

Chemotaxis by phagocyte

7

What is the second step of phagocytosis?

Adhesion of bacteria

8

What is the third step of phagocytosis?

Engulfment into phagocytic vacoule

9

What is the fourth step of phagocytosis?

phagosome

10

What is the fifth step of phagocytosis?

Phagolysosome formation

11

What is the sixth step of phagocytosis?

Killing and destruction

12

What is the seventh step of phagocytosis?

Release of debris

13

Which event occurs in the early stages of inflammation

Chemical mediators and cytokines are released

14

What is the function of selectins

They promote sticking of neutrophils to the inner vessel wall

15

True or False: Margination occurs when neutrophils stick to the lining of the endothelium

True

16

Which role does histamine play during inflammation

Leads to vasodilation

17

Extravastation, also known as diapedesis or transmigration, occurs when ____

Neutrophils squeeze through the vessel wall

18

Are interferons a first line of defense or a second line of defense?

Second

19

Evaluate the statements below, and select those that correctly apply to the role of PAMPs and PRRs in microbe recognition and phagocytosis.

  • PAMPs are molecules present only on microorganisms, and they serve as signal molecules for pathogen recognition.
  • Viruses do not contain PAMPs because they are not living cells.
  • PAMPs are signal molecules found on all organisms, and they help the immune system distinguish self from nonself.
  • PRRs are present at all times on phagocytic cells and even lymphocytes, regardless of whether they have encountered their corresponding PAMP.
  • Phagocytic cells, such as neutrophils and dendritic cells, only synthesize PRRs once they have encountered the corresponding PAMP
  • Peptidoglycan, LPS, and double-stranded RNA are all PAMPs since they are not present in eukaryotic cells.
  • PAMPs are molecules present only on microorganisms, and they serve as signal molecules for pathogen recognition.
  • PRRs are present at all times on phagocytic cells and even lymphocytes, regardless of whether they have encountered their corresponding PAMP.
  • Peptidoglycan, LPS, and double-stranded RNA are all PAMPs since they are not present in eukaryotic cells.

20

What are components that comprise the first line defense mechanisms?

Physical barriers, chemical defenses such as lysozyme and HCl, resident microbiota, and body functions such as sneezing, urinating, coughing, and vomiting

21

Normal biota appear to contribute to first line defense mechanisms through ____

antagonism

22

Similiar to macrophages, _______ cells are products of the monocytic cell line that reside throughout the tissues and present antigen to lymphocytes.

Dendritic

23

Select the nonspecific processes below:

Inflammatory response

complement cascade

Phagocytosis

Interferon production

Antibody production

Inflammatory response

Complement cascade

Phagocytosis

Interferon production

24

Fever enhances _____ and _____ mechanisms in the host

Metabolism; protective

25

When a cell is infected by a virus, synthesis of ______ begins and this protein diffuses away from the infected cell to protect nearby uninfected cells by binding to surface receptors and initiating synthesis of antiviral proteins.

Interferon

26

List the antimicrobial proteins

Interferons, complement, ATPase, Bacteriocin

27

Select the correctly described examples of host defense mechanisms.

  • Innate anatomical and physiological barriers
  • Innate cellular and chemical defenses
  • Innate host defenses due to B and T cells and their products
  • Use of drugs and antibiotics
  • Specific recognition of invaders by physical barriers
  • Innate anatomical and physiological barriers
  • Innate cellular and chemical defenses

28

MHC-I molecules are located on what type of cells?

All nucleated cells

29

True or False: MHC-I molecules normally display "self" proteins, those that are normally produced by a cell.

True

30

In the case of cancer or viral infection, which MHC class is involved with displaying abnormal proteins to cytotoxic T cells as a signal for destruction?

I

31

MHC-II molecules are located on what type of cells?

Macrophages, dendritic cells, and B cells

32

Helper T cells require antigen processing and presentation by MHC-___

II

33

What types of immunity do host defenses consist of?

Innate immunity and adaptive immunity

34

Adaptive immunity provides ___ (anamnestic response), ____ (antibody secretion), ____ (cell-mediated immunity)

Memory, antibody secretion, activated Tc and Th cells

35

Adaptive immunity is divided between

Active and passive immunity

36

True or false: first and second line defenses display antigen-specificity

False

37

What line of defenses displays immunologic memory

third line

38

What are the four major steps of a specific immune response?

Lymphocyte development

Antigen presentation

Challenge of B and T lymphocytes

B and T lymphocyte responses

39

_____ are substances that provoke a specific immune response which is so discriminating that only a single molecular fragment, called an _______, interacts with the lymphocyte’s receptor.

Antigens; epitope

40

Select the statements that accurately describe antigens.

Check All That Apply

  • They are perceived as foreign.
  • Only whole microbes can serve as antigens.
  • Proteins are immunogenic antigens.
  • Antigens provoke an immune response.
  • They are perceived as foreign.
  • Proteins are immunogenic antigens.
  • Antigens provoke an immune response.

41

What cell types serve as APCs

B cells, macrophages, and dendritic cells

42

What describes the primary action of B cells

B cells divide and differentiate forming plasma cells that secrete antibodies

43

What describes the method of Cytotoxic T cell-mediated killing of a target cell?

Apoptosis

44

What is the coating of microbe with antibody to enhance phagocytosis?

Opsonization

45

What antibodies fill the surface receptors on microbes to prevent its attachment to the host

Neutralization

46

What antibody that neutralizes bacterial exotoxins

Antitoxin

47

What crosslinkage of cells or particles into large clumps

Agglutination

48

True or false: Memory B cells are formed during the primary response so that upon a secondary antigen exposure, a faster and more
vigorous antibody response ensues.

True

49

A person's own body produces B and T cell responses to antigen stimulus

Active immunity

50

An individual receives immune substances that were produced by another host

Passive immunity

51

Immunity is acquired through normal life experiences, not through medical intervention

Natural immunity

52

Immunity is obtained through medical procedures such as immunization

Artificial immunity

53

Select the statements that pertain to the principle herd of immunity

  • Immune individuals do not carry the agent of a particular communicable disease.
  • Mass immunization confers indirect protection of non-immunized members.
  • Encounter with a pathogen is more likely in a largely immunized population.
  • Herd immunity is only maintained through the occurrence of natural disease.
  • Low herd immunity means there are greater numbers of susceptible individuals.
  • Immune individuals do not carry the agent of a particular communicable disease.
  • Mass immunization confers indirect protection of non-immunized members.
  • Low herd immunity means there are greater numbers of susceptible individuals.

54

Infections transmitted by arthropod biological vectors use which of the following portals of entry?

skin

55

Which is used by the greatest number of pathogens?

Respiratory tract

56

True or False: Nervous system diseases must always use the respiratory tract as a portal of entry because of its proximity to the brain.

False

57

Infections that are transmitted by ticks and other biting arthropods use what portal of exit

Blood removal

58

Pathogens that leave through feces are usually transmitted through ___ contact

Indirect

59

Pathogens that leave through the respiratory portal by sneezing or coughing are usually transmitted through _______.

Droplets

60

A pathogen can lead to attachment and avoidance of host defenses, which depend on ____

Virulence factors

61

Virulence factors may trigger ____ and _____

Toxemia and fever

62

Virulence factors may enhance _____

morbidity

63

What is the mode of transmission from lyme disease?

biological vector

64

What is the mode of transmission for salmonellosis from egg salad

vehicle

65

What are 3 ways a pathogen survives host defenses?

Avoiding phagocytosis, avoiding death inside phagocyte, and absence of specific immunity

66

what is the difference between signs and symptoms?

Sign: Objective manifestations of disease observed or measured by others

Symptoms: Subjective characteristics of disease felt only by the patient

67

True or false: Colonization of a body tissue by microbes most often results in the establishment of disease.

False

68

True or false: Resident microbiota can cause disease in some individuals if they gain access to the correct portal of entry.

True

69

The relative ability of a microbe to establish itself in a host and cause disease is referred to as ______.

Virulence

70

True or false: The presence of a capsule can enhance a microbe's virulence.

True

71

The ability of a nonpathogen or weakly pathogenic microorganism to cause disease primarily in an immunocompromised host is termed a(n) ______ infection.

opportunistic

72

What are the steps a microorganism take in process of establishing disease

Microbe enters through portal of entry, microbe attaches to receptor on host, microbe overcomes host defenses, disease is established

73

Select the statements that accurately reflect virulence factors.

  • Virulence factors only cause direct damage to host tissues.
  • Hemolysins break down the cell membranes of blood cells, damaging them.
  • Toxins are examples of virulence factors.
  • Bacterial capsules are not considered virulence factors for they do not directly damage the host.

Hemolysins break down the cell membranes of blood cells, damaging them.

Toxins are examples of virulence factors.

74

True or false: An infectious agent cannot be transmitted from a patient during the convalescent period.

False

75

True or false: reservoirs are always humans or other animals

False

76

A teacher walking through her first grade classroom pauses to pick up a used tissue that had ended up on the floor instead of in the waste basket. Unfortunately, after discarding the tissue, she doesn’t immediately wash her hands and acquires a strain of rhinovirus. Several days later, she begins to experience symptoms of a cold. Based upon this scenario, please select the mode of disease transmission demonstrated here.

Fomite

77

During 2007, there were 3.6 new cases of pertussis per 100,000 susceptible individuals in the United States, part of a steady increase that has been occurring since the 1980s. Select the term that is illustrated by this statistic.

Incidence