Body Defence

Question 1

Immune System

Answer 1

1. Bacteria
2. Viruses
3. Fungi
4. Toxins
5. pollution
6. parasites

Question 2

Antigen

Answer 2

anything capable of introducing the immune response

anything foreign to you as the host

Question 3

3 Levels of defenses

Answer 3

1. Nonspecific Immunity
   innate defenses
   surface barriers
2. Internal defenses
3. Has 2 arms
   - Humoral immunity (B cells)
   - Cellular Immunity (T cells)

Question 4

Body defences - nonspecific (innate)

Answer 4

born with it
general defence/ attack on all antigens
first and second line

Question 5

Body defences

Specific (acquired or adaptive)

Answer 5

Specialist/ targeted defence against on type of antigen.
acquired during life
3rd line

Question 6

Non specific properties

Answer 6

Do not distinguish between threats
react same each time at first
second line defences respond to tissue damage caused by pathogens or “mechanical” means

Question 7

What does First Line defences do?

Answer 7

Protects portal of entry

aim is to keep every invader out/ deny entry the SAME way via chemical and physical barriers.

Question 8

What does Second line defences do

Answer 8

Act once the microbes have entered the body

non- specific: Any invader inside is attacked the same way

Question 9

What are the 2 Antimicrobial Chemicals

Answer 9

Interferon

Complement

Question 10

What is Interferon?

Answer 10

Interferes with viral replication and activates immune cells

Question 11

What is Complement?

Answer 11

is a set of plasma proteins that ‘complements’ all aspects of the immune response

Question 12

What are the 2 Phagocytes

Answer 12

1. Phagocytosis

2. Phagocyte

Question 13

Phagocytosis

Answer 13

cell eating

Question 14

Phagocyte

Answer 14

cell that eats

Question 15

Natural Killer Cells

Answer 15

Immune surveillance - target abnormal cells

Question 16

Inflammation - Localised response

Answer 16

damaged cells send out chemical message 
body responds with inflammation 
destroys and removes antigens: immune response 
limits effects of injurious agents 
cleans up dead tissue and debris 
promotes healing

Question 17

Inflammation

Answer 17

1. more blood
2. phagocytes
3. healing

Question 18

Fever

Answer 18

systemic response
body tries to attain temperature above 37.2 - help by destroying bugs whose enzymes cannot work at high temperature.
higher metabolic rate to help healing.

Question 19

Third Line defences

Answer 19

develops on exposure to particular antigen
Antigen from microbes “wrong” cells
uses B and T lymphocytes made in bone marrow
B cells mature in bone marrow
T cells mature in thymus

Question 20

Properties of Specific defences

Answer 20

1. Specific
2. Versatile
3. Memory
4. Tolerance

Question 21

Specific

Answer 21

1 antigen - 1 response

Question 22

Versatile

Answer 22

Many threats

Question 23

Memory

Answer 23

formed after first exposure

Question 24

Tolerance

Answer 24

must exist towards town cell (antigens)

Question 25

Humoral immunity: B -lymphocytes

Answer 25

B cells make antibody (immunoglobulin) against the antigen; antibody-mediated immunity

Question 26

humoral immunity

Answer 26

antibodies work in the body humours (body fluids)

Question 27

Humoral immunity: Antibodies

Answer 27

stay in blood because they are big

Question 28

Defence against bacteria

Answer 28

Bacteria live between cells, on epithelial surfaces in fluid.
attacks mostly by antibodies from B cells
helped by non-specific defences.

Question 29

2 ways to activate B- cells

Answer 29

Phagocyte (APC) engulfs bacteria & “presents” antigens to helper T cells

Antigen attaches to antibodies on surface of B cells