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Flashcards in Body Defenses Deck (36)
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1

What are the characteristics of first line of defense?

skin, mucous membranes, normal flora

2

What are the characteristics of second line of defense?

phagocytes and natural killers, inflammation, complement system and interferons

3

What is the third line of defense?

Immune response
(T and B lymphocytes)

4

What the mechanical factors for first line of defense?

skin - keratin
mucous membrane - cilia

5

what are the chemical factors for first line of defense?

skin - pH and perspiration
mucous membrane - stomach lining (gastric juices)

6

what are the organisms that survive the gastric juices?

polio, hep.A, protozoal cysts, H.Pylori

7

what is the second line of defense?

non - specific and local

8

what is the function of macrophages?

they phagocytize the MO by: chemotaxis and opsonization

9

what is chemotaxis?

attraction to the chemistry of bacteria

10

what is opsonization

target can be tagged with antibodies or complement proteins

11

what are natural killer (NK) cells

they always look for foreign cells through MHC proteins

12

what happens if there are no MHC proteins

then they release cocktail of perforins and granenzymes

13

what is inflammation

normal and non specific response to an injury
vasodilation, vessel permeability, plasma infiltration

14

what is complement system

a series of proteins that react non-specifically to microbes

15

what can complement proteins cause?

cytolysis, inflammation and opsonization

16

what are three important aspects of immunity

specific, systemic, and memory

17

what is an antigen?

any foreign substance that elicits an immune response
must be large enough to be phagocytized by a macrophage

18

role of macrophages in immunity

present fragments of anitgens on their own cell membranes where they are recognized by lymphocytes

19

what is an epitope

the specific part of the antigen that we react to
it must be present to attack
all the viruses must have it
its very tiny

20

size of antigen

the antigen must be large enough to generate an immune system response
too small = hapten (like a prion)

21

what is the sequence of immunity

1. anitgen penetrates the body and enters blood or lymphatic system
2. macrophages phagocytize the antigen
3. epitope is displayed on surface of macrophage
4. initiation of AMI or CMI

22

what are two types of immune responses

cell mediated (CMI) and antibody mediated (AMI)

23

What is CMI

cell mediated immunity ( involves T cells)
Antigen-presenting macrophage stimulates production of several diff. types of T-cells
- Helper T cells produced which stimulate the activate of B cells and cytotoxin T cells
- cytotoxin T cells (killer)- destroy the infected cells using perforin and cytotoxins
-memory T cells-distribute throughout the body, multiply rapidly on next infection
-suppressor cells - shut everything down;inhibit plasma cells and cytotoxin T cells

24

what is AMI

- involves B cells
- B cells become plasma cells ( which make 2000/sec antibodies and they last for 4-5days)
- memory cells - lasts for years - responsible for secondary antibody response to same antigen

25

what are antibodies

proteins used by lymphocytes to bind to specific antigens

26

how to antibodies hurt microbes

agglutination
neutralization
opsonization
cytolysis

27

what is primary A/B response

IgM increases and peaks down to non-existent
IgG goes up at slower rate and peaks higher than IgM and suststains for longer period of time

28

What is secondary A/B response

IgG goes up by much faster rate because of the previous memory cells
stronger response and stays long term
the graph doesnt go back to baseline
the response is stronger, faster and stays for longer period of time

29

Overview of sequencess

Microbe in body -->macrophage phagocyte-->macrophages display antigen (epitope) --> can lead to B cell stimulation or T cell stimulation
if lead to B cell - plasma cells produced first and then memory
if lead to T cell --> helper T cells-->killer T cells -->memory-> surpressor

30

Acquired Immunity

active and natural - contract disease
active and artificial - vaccination
passive and natural - placental transmission, breast milk
passive and artificial - antiserum