CH 16 - Innate Immunity: Nonspecific defenses of the host

Question 1

Concept of Immunity
Susceptibility:
Resistance:
Immunity:

Answer 1

Susceptibility: ability to be productively infected
Resistance: unable to allow a productive infection
Immunity: an active process that prevents establishment or progression of infection

Question 2

Lysozyme

Answer 2

a small enzyme that attacks the peptidoglycan chain in cell walls of bacteria, causing the cells to burst

Question 3

Antibacterial substances

Answer 3

Sweat, saliva, sebum, urine

Question 4

Lysozyme

Answer 4

sweat, tears, saliva

Question 5

Leukocytosis

Answer 5

Increase in white cell count

Question 6

Leukopenia

Answer 6

Decrease in white cell count

Question 7

Neutrophils

Answer 7

Highest in white cell count
live only a short time
predominate early in infections

Question 8

Macrophages

Answer 8

lasts up to several months

predominate later in infections

Question 9

Phases of phagocytosis

Answer 9

The phases of phagocytosis:

1. chemotaxis and adherence of pseudopods
2. ingestion of target
3. formation of phagosome
4. fusion of phagosome with lysosome
5. digestion of target by digestive enzymes
6. formation of residual body
7. discharge of indigestible material

Question 10

Toll-like receptors

Answer 10

Toll-like receptors:
are protein molecules on cell surfaces throughout the body.
TLRs are how macrophages pseudopods adhere to bacteria.
TLRs recognize bacterially-produced molecules and signal the immune system via cytokines that bacteria are present.

Question 11

How do Strep. pyogenes and S. pneumonia evade phagocytosis?

Answer 11

they inhibit adherence due to the presence of M proteins, capsules.

Question 12

How do Staph. aureus evade phagocytosis?

Answer 12

they kill phagocytes due to the presence of leukocidins

Question 13

How do Listeria monocytogenes evade phagocytosis?

Answer 13

they lyse phagocytes through membrane attack complex

Question 14

How do Shigella, Rickettsia evade phagocytosis?

Answer 14

they escape phagosome

Question 15

How do HIV, M. tuberculosis evade phagocytosis?

Answer 15

they prevent phagosome-lysosome fusion

Question 16

How do Coxiella burnettii evade phagocytosis

Answer 16

survive in phagolysosome

Question 17

During inflammation, what are the signal molecules released by cell damage and their functions?

Answer 17

Histamine & Kinin: vasodilation and increased blood vessel permeability
Prostaglandins: Intensify effect of Histamine & Kinin; fever
Leukotrienes: increased blood vessel permeability

Question 18

what are the advantages of fever?

Answer 18

1. Increases interleukin (IL-1) activity
2. Increases transferrin
3. Produces interferon

Question 19

What are the disadvantages of fever?

Answer 19

Tachycardia; acidosis; dehydration; high temperature

Question 20

Describe the steps in the classical pathway of component Activation

Answer 20

1. C1 is activated by microbe-antibody complex
2. C1 causes C2 to split into C2a and C2b
3. C1 causes C4 to split into C4a and C4b
4. C2a and C4b combines to split C3
5. C3a and C3b initiate complement cascade
6. C3b causes opsonization
7. C3b also splits C5 into C5a and C5b
8. C5b, C6, C7, C8, C9 forms membrane attack complex
9. C3a and C5a causes inflammation

Question 21

Which of the complement cascades present in classical pathway are not involved in alternative pathway

Answer 21

C1, C2, and C4. Instead, host proteins, B,D, and P bind to microbes and combine with C3 to activate it.

Question 22

Lectin pathway of complement activation

Answer 22

C1 is not involved. Lectin binds to microbe and splits C2 and C4

Question 23

Which interferons cause cells to produce antiviral proteins.

Answer 23

IFN-alpha and beta

Question 24

Which interferon causes neutrophils and macrophages to phagocytize bacteria

Answer 24

IFN-gamma