Infection and Response Flashcards
(91 cards)
1
Q
Pathogens
A
Microorganisms that enter your body and cause disease
2
Q
What types of disease do pathogens cause
A
Communicable
3
Q
What can be infected by pathogens
A
- animals
- plants
4
Q
Types of pathogen
A
- bacteria
- virus
- protist
- fungi
5
Q
Bacteria
A
Very small living cells that reproduce rapidly in your body
6
Q
How do bacteria make you ill
A
Produce toxins that damage your cells and tissues
7
Q
Viruses
A
- live inside your cells
- 1/100 size of bacterium
- reproduce rapidly using cell’s machinery
8
Q
How do viruses make you ill
A
- cells full of virus copies burst
- cell damage makes you ill
9
Q
Protists
A
Single celled eukaryotes
10
Q
How do parasite protists cause damage
A
By living on or inside other organisms
11
Q
Vector
A
Something (often an insect) that carries protists to an organism without getting the disease itself
12
Q
Fungi structure
A
Some single celled OR some have body made up of hyphae (thread like structures)
13
Q
How do fungi cause disease
A
Hyphae grow and penetrate human skin and plant surface causing disease
14
Q
How can hyphae spread to other plants and animals
A
By producing spores
15
Q
How can pathogens be spread
A
- water
- air
- direct contact
16
Q
How does water spread pathogens
A
Some pathogens picked up by drinking or bathing in dirty, contaminated water
17
Q
How does air spread pathogens
A
- some pathogens are carried in air and breathed in
- some pathogens are carried in air in droplets produced when you sneeze or cough
18
Q
How does direct contact spread pathogens
A
Some pathogens picked up by touching contaminated surfaces, including skin
19
Q
Viral diseases
A
- measles
- HIV
- TMV
20
Q
How is measles spread
A
Inhaling droplets from infected person’s sneezes/coughs
21
Q
Measles symptoms
A
- red skin rash
- fever
- can lead to pneumonia
- can lead to encephalitis (brain inflammation)
22
Q
How is measles prevented
A
Receive vaccination when young
23
Q
How is HIV spread
A
- sexual contact
- exchanging bodily fluids (often when sharing needles when taking drugs)
24
Q
Effect of HIV
A
- initially flu-like symptoms for few weeks
- attacks immune cells
- no symptoms for several years
- develops into aids
25
HIV treatment
Antiretroviral drugs stop virus replicating in body
26
TMV
Tobacco mosaic virus
27
Effect of TMV
- mosaic pattern on plant leaves
- discolouration of leaves means plants can’t photosynthesis
28
Fungal disease
Rose black spot
29
How does rose black spot spread
- water
- wind
30
Effect of rose black spot
- purple or black spots on rose plants causing leaves to turn yellow and drop off
- less photosynthesis
31
How is rose black spot treated
- fungicides
- stripping plants of infected leaves and destroying them so they can’t spread to other plants
32
Protist disease
Malaria
33
How is malaria caused
- mosquito vectors pick up malarial protist by feeding on infected animal
- when mosquito feeds on another animal, inserts protist into animals blood vessels
34
Effect of malaria
- fever
- sometimes death
35
Malaria prevention
- stop mosquito breeding
- insecticides
- mosquito nets
36
Bacterial diseases
- salmonella
- gonorrhoea
37
Salmonella
Type of bacteria which causes food poisoning
38
Salmonella cause
- eating food contaminated with salmonella bacteria
- eating food prepared in unhygienic conditions
39
What causes salmonella symptoms
Toxins produced by the bacteria
40
Salmonella symptoms
- fever
- stomach cramps
- vomiting
- diarrhoea
41
Salmonella prevention
- most poultry in UK given vaccinations against it
- cook food properly
42
Gonorrhoea cause
Sexual contact
43
Gonorrhoea symptoms
- pain when urinating
- yellow/green discharge from vagina/penis
44
Gonorrhoea prevention
Barrier methods of contraception, like condoms
45
Gonorrhoea treatment
- originally penicillin, but strains have become resistant
- antibiotics
46
How to reduce/prevent spread of disease
- being hygienic
- destroying vectors
- isolating infected individuals
- vaccinations
47
How to be more hygienic to reduce/prevent spread of disease
- washing hands after sneezing to stop infecting another person
- washing hands before preparing food
48
How to destroy vectors to reduce/prevent spread of disease
- insecticides can kill insect vectors
- destroy insect vector’s habitats so they can’t breed
49
How can isolating infected individuals reduce/prevent spread of disease
Isolating people with communicable diseases stop them passing it on
50
How can vaccinations reduce/prevent spread of disease
Vaccinating against communicable diseases lessens likelihood of developing infection and passing it on
51
Parts of human body that stop pathogens getting in
- skin
- nose
- trachea and bronchi
52
How does skin stop pathogens getting in
- acts as barrier
- secretes antimicrobial substances which kill pathogens
53
How does nose prevent pathogens getting in
Hairs and mucus in nose trap particles that could contain pathogens
54
How do the trachea and bronchi prevent pathogens getting in
- trachea and bronchi secrete mucus from globlet cells to trap pathogens
- these are lined with cilia which waft mucus up to throat to be swallowed
- stomach produces hydrochloric acid to kill swallowed pathogens
55
How does the body detect pathogens
White blood cells travel all around the body looking for them
56
How do white blood cells deal with pathogens
- phagocytosis
- antibodies
- antitoxins
57
Phagocytosis
- phagocyte binds to pathogen
- phagocyte engulfs pathogen into cell and encloses it
- phagocyte secretes digestive enzymes to break down pathogen
- debris excreted
58
How do antibodies attack pathogens
- white blood cell detects unique antigens on pathogen surface
- antibodies produced to lock onto invading cells so they can be found and destroyed
- antibodies produced and carried round body to look for similar bacteria/viruses
- if person infected with same pathogen, same antibodies produced, they are immune
59
B-lymphocytes
White blood cells that produce antibodies
60
How do antitoxins attack pathogens
They counteract toxins produced by invading bacteria
61
How do vaccinations work
- inject small, amount of (harmless) dead pathogens carrying antigens
- body produces antibodies to attack them by clumping them together for phagocytes to engulf by phagocytosis, memory cells stay in blood
- if live versions of pathogen enter body, white blood cells can rapidly produce antibodies to kill it before it makes us ill
62
Advantages of vaccination
- controlled previously common communicable diseases in uk, smallpox gone, polio infections at 99%
- herd immunity - epidemics prevented if large percent of people vaccinated, unvaccinated people less likely to catch it if fewer people have it
63
Disadvantages of vaccination
- don’t always work
- bad reactions can occur but uncommon
64
Painkillers
- relieve pain by reducing symptoms
- don’t tackle cause or kill pathogens
65
Antibiotics
Kill bacteria causing problems without killing your body cells
66
How do bacteria become resistant to antibiotics
They mutate
67
How to slow down rate of development of resistant strains of bacteria
- doctors shouldn’t overprescribe antibiotics - only prescribe for more serious diseases
- finish full course of antibiotics
68
Why do many drugs come from plants
- plants produce chemicals to defend against pests/pathogens
- some of the chemicals can treat human diseases or relieve symptoms
69
Human medicines developed from plants
- aspirin
- digitalis
70
Aspirin
Painkiller used to lower fever
71
What was aspirin developed from
Chemical found in willow
72
Digitalis
Used to treat heart conditions
73
What was digitalis developed from
Chemical found in foxglove
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How was penicillin discovered
- Alexander Fleming was cleaning Petri dishes containing bacteria
- he noticed one dish had mould on and area around mould had no bacteria
- mould was producing penicillium notatum which killed the bacteria
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How are drugs made
- synthesised by chemists in labs
- may come from chemical extracted from plant
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Stages of drug development
- preclinical trials
- clinical trials
77
Stages of preclinical trials
- computer modelling
- tissues/cells
- animals
78
Computer modelling trial
- info about drug + 3D model go into computer, computer says if it will work - efficacy + toxicity
- computer says it will work - next stage
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Tissues/cells trials
- drug tested on living animal tissues/cells in petri dish to see if it will kill them
- cells survive - next stage
80
What drugs can’t be tested on human cells and tissues
Ones that affect whole or multiple body systems - must be tested on whole animal
81
Animals trials
- usually tested on rats - reproduce quickly
- then primates - biologically similar to humans
- animals survive - next stage
82
Stages of clinical trials
- healthy volunteers
- small number of patients
- large number of patients
83
Healthy volunteer trials
Test for toxicity, paid
84
Small number of patients trials
Test for efficacy + dosage, paid
85
Large number of patients trials
- **double blind test**
- used against placebo effect
- neither doctor or patient knows if substance is real drug or placebo
- volunteers paid
- success = peer review
86
Efficacy
Whether drug works and produces effect you’re looking for
87
Dosage
The concentration that should be given and goes often
88
Toxicity
Adverse side effects
89
Placebo
Substance like drug being tested but doesn’t do anything
90
Placebo effect
When a patient expects treatment to work so feels better, even through treatment isn’t doing anything
91
Are fungi prokaryotic or eukaryotic
Eukaryotic
