Human Defence System

Question 1

pathogen

Answer 1

disease causing micro organism

Question 2

immunity

Answer 2

ability to resist infection

Question 3

general defence

Answer 3

prevents the entry of microbes by acting as a barrier and destroying all microbes once they are within the body
it is non specific, attacks all pathogen types

Question 4

specific defence

Answer 4

identifies antigen and attacks particular pathogens using specific antibodies or white blood cells

Question 5

lymphocytes

Answer 5

type of white blood cell that kills a pathogen by producing antibodies or killing a body cell that displays an antigen

Question 6

monocyte

Answer 6

type of white blood cell that develops into a macrophage, that engulfs a pathogen and displays antigens on itself, stimulating the production of antibodies

Question 7

antibody

Answer 7

proteins produced by lymphocytes in response to an antigen

their role is to inactivate antigens

Question 8

antigen

Answer 8

foreign molecule that stimulate the production of antibodies

Question 9

vaccination

Answer 9

non disease causing dose of the pathogen that is introduced into an organism to stimulate the production of antibodies

Question 10

induced immunity

Answer 10

when the body contains specific antibodies against particular antigens

Question 11

active immunity

Answer 11

when a person can produce their own antibodies against a disease

Question 12

passive immunity

Answer 12

when a person cannot produce their own antibodies against a disease and receives antibodies that have been made by another organism

Question 13

autoimmune disease

Answer 13

when part of the body is attacked by its own immune system

Question 14

first line of defence

Answer 14

skin
mucus
HCI
lysozyme
bacteria

Question 15

first line of defence SKIN

Answer 15

physical barrier preventing entry of pathogens, sebaceous glands to produce sebum that kills bacteria

Question 16

first line of defence MUCUS

Answer 16

traps pathogens and cilia push mucus out, pathogens are then swallowed and killed in the stomach by HCI

Question 17

cilia

Answer 17

small hairs lining the tubes of the respiratory system

Question 18

first line of defence HCI

Answer 18

in stomach

kills pathogens

Question 19

first line of defence LYSOZYME

Answer 19

bursts bacteria which allows the entry of water to their cells

Question 20

first line of defence BACTERIA

Answer 20

lactic acid produced in the vagina inhibits the growth of pathogens

Question 21

second line of defence INFLAMMATION

Answer 21

infected cells release a chemical that causes blood capillaries to dilate
swelling and redness is caused at the site of infection, number of WBCs at the site of infection increases
fever can occur, body temp increases which interferes with reproduction of some bacteria and viruses

Question 22

second line of defence WBCs

Answer 22

phagocytes engulf and destroy micro organisms

Question 23

complement defence proteins

Answer 23

activated by infection, produce holes in bacterial walls causing the bacterial cells to fill with fluid and burst

Question 24

interferon defence proteins

Answer 24

released by cells infected by viruses, prevents the multiplication of viruses and limits the spread of virus infection

Question 25

specific immune system

Answer 25

identifies antigen and attacks particular or specific pathogens using specific antibodies or WBCs

Question 26

organs/glands specific to the immune system

Answer 26

tonsils lymph nodes spleen thymus gland

Question 27

white blood cells

Answer 27

formed in bone marrow and some mature in spleen no nucleus present, no definite shape less numerous than RBCs defend against disease by engulfing and destroying cells and displaying antigens or producing antibodies

Question 28

types of lymphocytes

Answer 28

T cells: dont produce antibodies | B cells: produce antibodies

Question 29

T cells

Answer 29

``` form in bone marrow mature in thymus gland helper t cells killer t cells suppressor t cells memory t cells ```

Question 30

helper t cells

Answer 30

recognise antigens, activate killer t cells | stimulate b cells

Question 31

killer t cells

Answer 31

recognise the infected cell, produce perforin to kill infected cells - perforates cell membrane

Question 32

suppressor t cells

Answer 32

stop immune response by inhibiting b cell or t cell production

Question 33

memory t cells

Answer 33

remember antigen and survives a ling time to allow long term protection

Question 34

b cells

Answer 34

form in bone marrow mature in red bone marrow plasma b cells memory b cells

Question 35

plasma b cells

Answer 35

antigens recognised, plasma b cells multiply antibodies specific to the antigen produced in response antigen inactivated antigen disposed: by phagocytes or complement system

Question 36

memory b cells

Answer 36

survive long after infection convert plasma b cells in response to infection when it returns, secondary response (active immunity). therefore, these cells respond more rapidly than original b cells

Question 37

antigen response by b lymphocytes

Answer 37

1. pathogen displays antigens 2. b lymphocytes recognises antigen and produces specific antibodies in response to the antigens 3. antibodies bind to antigens and lymphocytes engulf and destroy pathogen

Question 38

active vs passive immunity

Answer 38

active - longer lasting | passive - shorter lasting than active, needed for the fast response to infection

Question 39

an antibody may be given instead of vaccination if

Answer 39

the infection has already occurred or is possibly very dangerous

Question 40

reasons we don't get the same infection twice

Answer 40

lymphocytes produce more antibodies faster than first infection, so smaller amounts of antigens present

Question 41

how antibiotic resistance develops

Answer 41

not completing a full course of antibiotics or misusing them bacteria mutate and acquire resistance, this resistant gene is carried in the plasmid resistant plasmid is passed on

Question 42

why are antibiotics not prescribed for the flu

Answer 42

not effective against viruses flu is caused by influenza virus antibiotics are prescribed to kill bacterial infections

Question 43

immunosuppressants

Answer 43

antirejection drugs taken by organ transplant patients or to treat autoimmune diseases these inhibit or prevent the activity of the immune system people on these are more prone to infection

Question 44

why covid affected older people

Answer 44

immune system gradually declines in a process called immunosenecence

Question 45

why covid doesnt affect children

Answer 45

t cells are mostly untrained, greater capability to respond to new viruses children regularly catch common cold, antibodies give some form of protection