CHAPTER 14: SECOND LINE OF DEFENSE

Question 1

second line of defense actions

Answer 1

• recognition
• inflammation
• phagocytosis
• interferon
• complement

Question 2

Inflammation: 4 major signs

Answer 2

• redness: inc circ and vasodilate in injured tissues
• warmth: heat from inc blood flow
• swelling: inc fluid, vasodilate (edema), WBC/microbes/fluid can collect as pus
• pain: stim nerve endings from pressure or released chemicals

Question 3

inflammation primary functions

Answer 3

• loss of function
• mobilize and attract immune components to site of injury
• destroy and block microbes from further invasion

Question 4

chronic inflammation- why is it bad

Answer 4

• cause of tissue injury and autoimmune disease

Question 5

inflammation: immediate reaction post injury

Answer 5

• vasoconstrict for clot formation
• mast cells release chem stimulators, cytokines and chemokines to regulate defenses

Question 6

major events in inflammation

Answer 6

• vasc reaction after clot form, nearby vessels dilate (influx og immune components, cause redness and warmth)
• edema and pus formation (collect fluid/exudate, influx neutrophils, fluid dilute toxins)
  pus made of WBC, microbe, debris

Question 7

major events in inflammation: resolution/scar formation

Answer 7

• site of damage last more than few days–> attract monocyte, lymphocyte, macrophage

fibroblast for repair/replace damaged tissue

Question 8

phagocytosis- activities

Answer 8

• survey tissue compartments, find microbes
• ingest and ELIMINATE
• extract immunogenic info

Question 9

phagocytosis- neutrophils, eosinophils, macrophages actions

Answer 9

Neutro: react early to bacteria, main part of pus

eosin: attracted to PARASITE infections

macrophage: from monocyte, process foreign substance and prep for B/T cell reactions

Question 10

leukocyte characteristics: chemotaxis and diapedesis

Answer 10

chemo: response to chemical at injury site (chemokine, endotoxin, PAMP)
- cause WBC to migrate to wound

diap: cells leak out of blood vessels and into tissue (leukocyte extravasation, leuk walking)

Question 11

Pyrogen

Answer 11

• substance that induces fever
• use hypothalamus to inc body temp
• tell muscles inc heat and vasoconstrict

Question 12

exogenous vs endogenous pyrogens

Answer 12

exo: products of infectious agents (LPS of gram -)

endo: liberated by monocytes, neutrophil, and macrophage during phago
- interleukin 1 and tumor necrosis factors

Question 13

benefits of fever

Answer 13

• hurts temp sensitive microbes
• bacteria cant have iron as a nutrient
• inc metab and immune reaction

but.. TOO high of a fever is BAD.

Question 14

Recognizing foreign cells- macrophage
- TLRs
- what does it detect specifically
- how does the cascade work w the TLR

Answer 14

• macrophage cell memb has Toll like receptors (TLR)
• 10 types act as PRR to recog PAMPs
• recog dsRNA or LPS, not specific for the pathogen just the MOLECULE
• signal macro to produce chem to stimulate immune response

each TLR one half, foreign molecules joins in a dimer, starts signal cascade to nucleus turn on genes that control immune response, PRODUCT turns off genes

Question 15

Phagocytosis: when does it occur/how (general statement)

Answer 15

after chemotaxis–> phagocytes migrate and recog PAMPs (phagosome)

Question 16

phagolysosome

Answer 16

phagosome fused with lysosome

Question 17

phagocytosis: how is the bacteria destroyed
- oxygen used, neutrophil and lysosome actions, PAD4, neutrophil net

Answer 17

• phagosome use oxygen dep syste, and unstable toxic oxygen forms (ex: singlet O2)
• neutrophils dont live long bc of toxic/reactive O2 forms
• lysosome has toxic chem–> when fuse to phagosome that HAS the bacteria, it will KILL it
• PAD4 unpackage chromosome of neutro and send out w lethal agents on it

this net kills other bacteria, nucleases chop it up, macrophages remove it

Question 18

phagocytosis: process creates what?

Answer 18

autoantibodies that can develop into an autoimmune disease

Question 19

Interferons: what is it

Answer 19

• chemicals that have downstream effects on cells
• small proteins made by WBC and tissue cells

Question 20

Interferons: types of proteins

Answer 20

interferon alpha: lymphocytes and macrophage
interferon beta: fibroblasts and epithelial cells
interferon gamma: T cells

Question 21

Interferons: why are they made

Answer 21

in response to viruses, RNA, immune products, and antigens

• tell your body that cancer cells are present, and induce expression of antiviral proteins that inhibit expression of cancer genes

Question 22

interferons: how do they work

Answer 22

• when the cell detects an infection, turns on beta, and the neighboring cells can sense the interferon
• signals to other cells that a virus is nearby and tells it to turn antibody defenses on HIGHER
• turns on series of antiviral proteins to make it less hospitable to the virus trying to infect it

Question 23

Complement
- made up of what
- where is it made
- purpose
- how are the proteins activated

Answer 23

• 26 blood proteins work together to destroy bacteria/viruses
• made in LIVER (hepatocytes, lymphocytes, monocytes)
• come together to make holes in cell membrane
• activated by cleavage

CASCADE: diff proteins touch one another and activate each other