immunology option Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

how does a pathogen try and get into the body?

A

tries to enter through body through hole e.g. eyes, cuts
pathogen enters body tissue and tries to reach blood supply via a capillary
(responses include inflammation and phagocytosis)
pathogen enters blood supply and can migrate around body target cells to reproduce
(response includes B, T and memory cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the first line of defence?

A

natural barriers
e.g. eyes, skin, ears

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how do eyes protect against pathogens?

A

produce tears containing antibodies and lysozymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how do ears protect against pathogens?

A

produce wax which traps pathogens and contains lysozymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what does ciliated mucous membranes do in the gut, genitals, anus, ears, nose and respiratory pathways?

A

sticky mucus lines passage to trap pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how does the respiratory tract protect against pathogens?

A

ciliated cells which waft mucus to the top of the trachea, mucus is swallowed and passes into stomach acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what does the epithelial layer of cells do to protect against pathogens?

A

contains mucus producing goblet cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how does the skin protect against pathogens?

A

outer layer of epidermis
consists of dead keratinised cells
act as a physical barrier

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what does skin flora do?

A

commensal bacteria which competes with pathogenic bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does the mouth protect against pathogens?

A

lysozyme in saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does the urethra protect against pathogens?

A

flow of urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how does the vagina protect against pathogens?

A

acidic
mucus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how does blood clotting protect against pathogens?

A

seals wound to prevent pathogen from entering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is lysozyme?

A

in tears and saliva
enzyme attacks peptidoglycan in cell walls of gram-positive bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the second line of defence?

A

inflammation
phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does inflammation cause?

A

redness
swelling
heat
pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the function of inflammation?

A

increase blood flow to the area
destroy cause of infection replace and repair damaged tissue
limits effects on body by confining infection to small area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does phagocytosis do?

A

localises any break in barrier and destroys invading microorganisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are phagocytes?

A

non specific white blood cells
(neutrophils and macrophages)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what do neutrophils and macrophages do?

A

engulf and digest foreign particle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what happens during phagocytosis?

A

chemotaxis and adherence of microbe to phagocyte
ingestion of microbe by phagocyte (engulf)
formation of phagosome with lysosome to form phagolysosome
digestion of ingested microbe by enzymes formation of residual body and discharge of waste materials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what do neutrophils do?

A

engulf and destroy pathogens
numbers rise as a result of infection
short lived

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what do macrophages do?

A

engulf pathogen and then present antigen on surface
long lived
settle in lymph nodes, spleen and kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the third line of defence?

A

response to an antigen involving lymphocytes due to antigens being recognised as foreign

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is the humoral response?

A

B lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is the cell mediated response?

A

T lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what are antigens?

A

proteins/polysaccharides/glycoproteins
specific shape
on surface of bacteria/virus/foreign tissue
can be free molecules e.g. toxins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what are antibodies?

A

large protein molecules that can recognise and neutralise antigens
specific shape complementary to that antigen
quaternary structure proteins (2 heavy, 2 light chains)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what are the 3 ways antibodies are able to combat pathogens?

A

neutralisation
aggulation
opsonisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what happens during neutralisation?

A

antigens which are toxic are rendered harmless if blocked by being bound to an antibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what happens during aggulation?

A

forming antibody-antigen complexes so pathogens are held together in large clumps
pathogens cannot move and invade cells
macrophages and neutrophils can move more easily to engulf pathogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what happens during opsonisation?

A

antibodies coat antigens to help the immune system recognise them
phagocytes have receptors which enable them to bind to and engulf microbes coated with antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what are the properties of lymphocytes?

A

produced by stem cells in bone marrow
have specialised receptors on plasma membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what do B lymphocytes do?

A

originate in bone marrow
mature in spleen and lymph nodes
develop into plasma B cells (and memory)
plasma B cells secrete antibodies
memory B cells remain in body for years and act as an immunological memory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what do T lymphocytes do?

A

originate in bone marrow
migrate to thymus gland to mature
develop into T helper, killer, memory and suppressor cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what do T helper cells do?

A

release cytokines which stimulate B lymphocyte cells to develop and stimulate phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what do plasma B cells do?

A

secrete antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what do T killer cells do?

A

attack and kill infected cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what do T suppressor cells do?

A

turn off immune response when infection is cleared

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what happens to cells with self-antigens?

A

deleted soon after formation otherwise our own body cell would be destroyed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

why do you feel ill for a period of time before getting better?

A

body produces millions of B and T lymphocytes which are all specific to different antigens
time is taken to find the right cell and then for that cell to increase in number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what is the function of clonal selection?

A

to activate B and T lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

what happens during clonal selection?

A

pathogen enters body and produces toxin
phagocytosis and antigen presentation by macrophages
macrophages must find specific B and T cell that is complementary to bind to antigen
antigen binds to complementary receptor of B or T cell so cell is activated
selected cell then divides rapidly by mitosis (clonal expansion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what is the cell mediated response?

A

when T cell is clonally selected so differentiates into killer, helper and memory T cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what is the humoral response?

A

when a B cell is clonally selected so differentiates into plasma and memory B cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

why is there a delay (lag phase) on graph?

A

due to clonal selection and expansion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

where is there not a delay (lag phase) if infected for a second time?

A

memory B cells are present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what is natural immuntiy?

A

gained in normal course of living processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

what is artificial immunity?

A

gained by deliberate exposure to antigens/antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what is active immunity?

A

caused by introduction of the antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

what is passive immunity?

A

introduction of antibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

what is an example of passive natural immunity?

A

antibodies are given via placenta or breast milk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what is an example of passive artificial immunity?

A

antibodies given by injection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

what is an example of active natural immuntiy?

A

antibodies made by persons own immune system from infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

what is an example of active artificial immunity?

A

antibodies made by immune system from vaccination

55
Q

what is the definition of vaccination?

A

deliberate exposure to harmless antigenic material to activate immune response

56
Q

what are examples of antigenic materials?

A

whole live microorganism
dead microorganism
harmless microorganism
toxoid (harmless form of toxin)

57
Q

what do immunisation programmes do?

A

give boosters over several years to make sure that enough immunity is required to give long term protection

58
Q

why can vaccinations not be effective sometimes?

A

some people don’t have strong enough immune systems
malnutritions (antibodies are made of proteins)
antigenic variation caused by mutation, antigens no longer recognised by immune system

59
Q

what is antigenic shift?

A

mixing of antigens between similar strains of virus to produce a new strain

60
Q

what is antigenic drift?

A

accumulation of mutations over time
genetic mutations leading to new different shaped antigens that produces a new strain

61
Q

what are the features of bacteria?

A

prokaryote
no membrane bound nucleus
no membrane bound organelles
small ribosomes
cell wall made of peptidoglycan
flagellum
pili
slimy capsule

62
Q

what does peptidoglycan do?

A

prevents osmotic lysis
maintains pressure inside cell
provides structure and rigidity

63
Q

what shape is bacillus bacteria?

A

rod-shaped

64
Q

what shape is coccus bacteria?

A

spherical (balls)

65
Q

what shape is spirillum bacteria?

A

spiral

66
Q

what colour does gram positive bacteria stain?

A

purple

67
Q

what colour does gram negative bacteria stain?

A

pink

68
Q

why does gram positive bacteria stain purple?

A

thick layer of peptidoglycan
cell wall retains crystal violet dye

69
Q

why is penicillin effective against gram positive bacteria?

A

weakens cell wall causing cell to burst

70
Q

why does gram negative bacteria stain pink?

A

thinner peptidoglycan layer and protective outer layer of lipopolysaccharide and lipoprotein outside of cell wall
cell does not retain crystal violet dye

71
Q

why is penicillin not effective against gram negative bacteria?

A

cell wall is resistant due to lipopolysaccharides

72
Q

what are the properties of E.coli?

A

rod-shaped
gram negative (stain spink)
in gut

73
Q

what are the properties of B.subtilis?

A

rod-shaped
gram positive (stains purple)
in soil

74
Q

what are antibiotics?

A

chemicals produced by fungi and bacteria to interfere with biochemistry of bacteria
can be used without harming human cells
cannot be used against viruses

75
Q

what are the two types of antibiotics?

A

bacteriostatic
bacteriocidal

76
Q

what does bacteriostatic antibiotics do?

A

slow down or prevent bacteria from growing

77
Q

what does bactericidal antibiotics do?

A

kill bacteria

78
Q

what are broad spectrum antibiotics?

A

effective against a wide range of pathogenic bacteria
usually affect common processes e.g. photosynthesis

79
Q

what are narrow spectrum antibiotics?

A

only effective against a few types of bacteria and affect more specific processes

80
Q

what types of bacteria do penicillin affect?

A

kills gram positive
narrow spectrum
bactericidal
readily diffuses through cell wall

81
Q

what does penicillin do?

A

affects formation of cross linkages in peptidoglycan when new cells are formed
cell wall is weakened so bacterium is likely to burst
then is vulnerable to attack by immune system

82
Q

what does tetrecycline do?

A

inhibits translation in protein synthesis
inhibits second binding site on 30s ribosomes
prevents binding of tRNA molecules to complementary codon
broad spectrum
bacteriostatic

83
Q

why are antibiotic sensitivity tests carried out?

A

to find most appropriate antibiotic to use on bacterial infection

84
Q

how does antibiotic resistance occur?

A

bacteria shows genetic variation due to e.g. mutation
bacteria can pass resistant DNA to non-resistant one during sexual reproduction
when given antibiotic, resistant bacteria survive
surviving bacteria reproduce asexually to form identical clones and pass on resistant gene
population of antibiotic resistant bacteria are produced

85
Q

what causes antibiotic resistance?

A

if prescribed for trivial infections
if people do not complete prescribed course of antibiotics
used routinely in intensive farming

86
Q

what are the properties of viruses?

A

very small
can only reproduce in host cells
contain DNA or RNA
surrounded by protein coat (capsid)

87
Q

what are the 3 ways viruses can cause pathogenic effects?

A

cell lysis
can trigger cells to become cancerous
surpress immune system

88
Q

what does the lytic cycle look like?

A

loop
attachment and entry
replication
assembly and release

89
Q

what does the lysogenic cycle look like?

A

integrates into hosts genome
entry and becomes part of DNA
replication

90
Q

why are there 3 subgroups of influenze?

A

all caused by the same virus but with different antigenic types

91
Q

what is influenza A?

A

infects humans, birds, pigs
(like influenza B)

92
Q

what is influenza C?

A

causes mild upper respiratory tract illness
no vaccine

93
Q

what are the antigenic types of influenza based on?

A

differences between two surface proteins

94
Q

what are the two surface proteins of influenza?

A

H = haemagglutinin
N = neuraminidase

95
Q

how is influenza transmitted?

A

person to person by droplet infection
infects cells of upper respiratory tract

96
Q

what are the influenza symptoms?

A

headache
chills
coughs
fever
apetite loss
tiredness
muscle aches
destructions of respiratory epithelium

97
Q

how can you treat influenza?

A

anti-viral drugs

98
Q

how can you prevent influenza?

A

vaccination programmes

99
Q

what is small pox caused by?

A

DNA-containing virus
Variola major

100
Q

how is small pox transmitted?

A

by saliva
person to person contact
inhaled
enters small blood vessels in skin, mouth and throat

101
Q

what are the symptoms of small pox?

A

rash followed by fluid filled blisters (leaves scars)
scars on cornea result in blindness

102
Q

what is the treatments for small pox?

A

infected people are isolated
given fluids/drugs to control fever
antibiotics for secondary infections

103
Q

why was the small pox vaccination programme a success?

A

low rate of mutation so little antigenic variation
no animal reservoir for virus

104
Q

what is a carrier?

A

individual that shows no sign of infection but can spread the disease

105
Q

what is an endemic?

A

a disease which is always present at low levels in an area

106
Q

what is an epidemic?

A

a significant increase in the number of cases in an area
often spreading rapidly

107
Q

what is a pandemic?

A

an epidemic spreading world wide or across a large area

108
Q

what is a vector?

A

a living organism which transfer a disease from one individual to another

109
Q

what is a toxin?

A

a chemical produced by a microbe which causes damage to its host

110
Q

what bacteria causes cholera?

A

vibrio cholerae

111
Q

what are the properties of vibrio cholerae?

A

gram negative
comma-shaped
motile as flagellum allows it to move through water

112
Q

what does vibrio cholerae do in the body?

A

lives and multiples in the intestine
produces powerful endotoxin
causes inflammation of mucous membrane of gut

113
Q

how does cholera spread?

A

contaminated water by faeces containing organism
contaminated food
direct contact between people

114
Q

what are the symptoms of cholera?

A

diarrhoea due to irritation of bowel by the endotoxin
dehydration and loss of mineral salts

115
Q

what is the treatment for cholera?

A

rehydration salts
non-contaminated fluids
anti-bacterial drugs

116
Q

how can you prevent cholera?

A

proper disposal of human faeces (sewage system)
education

117
Q

what cause tuberculosis?

A

mycobacterium tuberculosis

118
Q

how is tuberculosis transmitted?

A

airborne droplets from coughs and sneezes
in crowded conditions

119
Q

what are the symptoms of tuberculosis?

A

attacks lungs and lymph nodes
fever/chills
coughing up blood
weakness/fatigue/loss of appetite
shortness of breath

120
Q

how can you detect tuberculosis?

A

the heaf test

121
Q

what is the vaccine for tuberculosis?

A

BCG vaccination

122
Q

what is malaria caused by?

A

plasmodium
(protoctistan parasite)

123
Q

what is the vector called that malaria is caused by?

A

female Anopheles mosquito

124
Q

what are the four species of plasmodium?

A

P.falicparum
P.vivax
P.ovale
P.malariae

125
Q

how is malaria transmitted?

A

infected mosquito bites human
plasmodia in mosquitos saliva enters bloodstream
invades liver and multiplies and infects blood
another mosquito picks up plasmodium after bite
sexual reproduction in mosquitos intestine produces plasmodia which migrates to salivary glands
mosquitos infects others

126
Q

how does reproduction occur in plasmodium?

A

plasmodium invades red blood cells and multiplies
plasmodia reproduce asexually in blood
red blood cell ruptures and releases plasmodium

127
Q

what are the symptoms of malaria?

A

headache
coma
repeated vomiting
generalised convulsions
fever
severe anemia

128
Q

how can you control malaria (reduce bites)?

A

hang mosquito nets
use insect repellants

129
Q

how can you control malaria (kill vector or reduce vector numbers)?

A

drain standing water
introduce fish to eat mosquito larvae
spray water surface with diesel oil to stop larvae breathing
spray water with pathogenic bacteria to kill larvae
spray water with insecticide
release sterilised male mosquitos

130
Q

what are the advantages of living vaccines?

A

behaves same as infectious agent
stimulates powerful response

131
Q

what are the disadvantages of living vaccines?

A

could mutate to become pathogenic
can cause disease

132
Q

what are the advantages of dead vaccines?

A

unable to cause disease
easy to store

133
Q

what are the disadvantages of dead vaccines?

A

may not get as strong a response

134
Q

what are the advantages of RNA/DNA vaccines?

A

safe as no chance of disease
focuses immune system on particular antigen

135
Q

what are the disadvantages of RNA/DNA vaccines?

A

only protects against one particular antigen