Ch.14

Question 1

What are the bodily responses involved in the innate immune defenses?

Answer 1

• Interferon (IFN) secreted with viral infection
• Phagocytes engulf microbes or cell debris by phagocytosis
• Inflammatory response is coordinated
• **Fever ** interferes with pathogen growth and enhances other immune responses

Question 2

What are the bodily responses involved in adaptive immune defenses?

Answer 2

• the activation of B lymphocytes (B cells) to produce antibodies against a particular pathogen
• the activation of T lymphocytes (T cells) to directly attack infected cells

Question 3

How do skin and mucous membranes protect the body from microbial pathogens?

Answer 3

• skin membranes continually flake off along with any attached microbes
• mucous membranes move microbes toward areas where they can be eliminated

Question 4

What two functions do phagocytes serve in immune responses?

Answer 4

Engulfment/destruction of foreign cells AND alerting the other cells of the immune system to an invader.

Question 5

Lymphocyte cells

Answer 5

• B cells, T cells highly specific in recognition of antigen
  – Generally reside in lymph nodes, lymphatic tissues

Question 6

What is the function of neutrophils and how do they act?

Answer 6

• act as “SWAT team”
• Rapid response; move into area and eliminate invaders
• Kill microbes via phagocytosis and release of granule content
• Can release DNA to form neutrophil extracellular traps (NETs) catching microbes, allowing enzymes and peptides from granules to destroy them
• Die once granules used

Question 7

What are the chemicals that act like “voices” of a cell, which carry messages and call the “alert system” that an invader has entered?

Answer 7

Cytokines

Question 8

What is the compliment system?

Answer 8

• The complement system “complements” activities of adaptive immune system

Question 9

How does the classical pathway of the compliment system work?

Answer 9

activated by antibodies bound to antigen, which interact with complement system

Question 10

How does the alternate pathway of the compliment system work?

Answer 10

triggered when C3b binds to foreign cell surfaces (C3 unstable, so some C3b always present)

Question 11

Interferon helps protect against viruses. How does interferon work?

Answer 11

• causes neighboring cells to express inactive antiviral proteins (iAVPs) activated by viral dsRNA
• Degrade mRNA, stop protein synthesis, infected cells undergo apoptosis

Question 12

Following digestion of a microorganism by phagocytosis, how is the debris excreted?

Answer 12

Exocytosis: vesicle fuses with cytoplasmic membrane, expels remains

Question 13

What are the 4 cardinal signs of inflammation?

Answer 13

swelling, redness, heat, pain, loss of function

Question 14

How does fever help the body fight off invading pathogens?

Answer 14

• Fever is indicator of infection, especially bacterial
• Temperature-regulation center in brain normally holds at 37 degrees Celsius but raises during infection in response to fever- inducing cytokines called pyrogens