B-3 Infection and response Flashcards
1
Q
What is a pathogen
A
- Pathogen is a microorganism that can cause infection disease
- may be bacteria, virus, protists or fungi
- Can be seen in plants or animals.
2
Q
What are the characteristic of viruses and bacteria
A
- Bacteria- very small cells- reproduce rapidly- may produce toxins that damage cells and produce toxins
- Virus- not cells- tiny- reproduce rapidly inside body live inside cells and replicate- spread- cell damage makes you feel ill- burst and release new virus
3
Q
What are the characteristics of Fungi and protists
A
- Protists- All eukaryotes- most single celled- some parasites- live on or inside organisms and cause damage
- Often carrie day vector who does not get disease
- Fungi- Single celled or body made fro hyphae- grow and penetrate human skin and surface and skin causing disease
- Can produce spores which spread to other plants and animals
4
Q
- How can pathogens spread
A
- Water- Drinking or bathing- e.g cholera.
- Air- carried in air and breathed in- cough or sneeze e.g influenza virus
- Direct contact- Touching- e.g skin. E.g athletes foot
5
Q
- What is measles
A
- Viral disease showing symptoms of fever and red skin
- Serious can be fatal with complications
- Spread through inhalation of droplets from infected persons sneezes of coughs
- Children are vaccinated against it
6
Q
- What is HIV
A
- Initially causes flu like symptoms - can feel no symptoms for years after
- Unless controlled with antiretroviral drugs it can attack immune system
- Can cause AIDS when boys immune system becomes so weak it cannot cope with infection or cares
- Spread by sexual contact or exchange of bodily fluids- e.g needles
7
Q
What is Tobacco mosaic virus
A
- Plant pathogen affecting many species of plants including tomatoes
- Causes mosiac pattern - discolouration
- Lack of photosynthesis - lac of growth
8
Q
What is Rose black spot
A
- A fungal disease where purple or black spots develop on the leave- often turn yellow and drop
- Photosynthesise reduced- growth-
- Spread in water or wind
- Treated using fungicides and removing affected leaves
9
Q
What is malaria
A
- Pathogens cause malaria are protists
- Life cycle that includes mosquito
- Causes episodes of fever- can be maya;
- Prevent vectors from breeding and using mosquito nets
10
Q
What is salmonella
A
- Food poisoning spread by bacteria - secrete toxins
- Fever, stomach cramps, vomiting and diarrhoea
- Uk most poultry vaccinated- limits spread
- Contaminated eating
11
Q
- WHAT IS GONORRHOEA
A
- STI-
- Thick yellow discharge and pain when urinating
- caused by bacteria
- Used to be easily treated with penicillin- became resistant
- Barrier method anti antibiotics
12
Q
What can be done to reduce the risk of the spread of disease
A
- Being hygienic- stop you infecting
- Destroying vectors- protists cannot be transferred
- Isolating infected individuals- stops spreading
- Vaccination- Can’t get it
13
Q
What is the non-specific defence system
A
- Skin- Barrier- antimicrobial substance- kill pathogens
- Hairs and mucus- trap practices that contain pathogens
- Trachea and bronchi- Cilla- waft mucus that contains pathogens back up
- Stomach- hydrochloric acid- kill
14
Q
What are phagocytes
A
- White blood cells
- Engulf and digest
- Foreign cells
15
Q
What role do white blood cells have on your immune system,
A
- Travel around and attack and destroy pathogens
16
Q
What are lymphocytes- Antibodies
A
- Every pathogen has unique antigens on surface
- When white blood cells come across foreign antigen they produce antibodies-
- These antibodies lock on so they can be found and destroyed by other white blood cells- try new antigens - will only lockout that one
- Antibodies produced rapidly and carried to do to all cells
- Stored as memory lymphocytes so if they come back again can be destroyed quickly
17
Q
What are antitoxins
A
-Toxins produce by the living bacteria
18
Q
What does vaccination involve
A
- Introducing small amounts of dead or inactive forms of pathogens into body
- Stimulates white blood cells to produce antibodies
- If the same disease comes back the memory lymphocyte will know the antibody needed
19
Q
How does vaccination prevent illness on a population level
A
- If large proportion of population is immune the spread is very limited
- Disease may even disappear
- Herd immunity
- Can re-appear
- Whopping cough- 1980s- safety concerns- substantial number does
20
Q
- What are the pros and cons of vaccines
A
Pros-
- Helped control lots of disease e.g polio, whooping cough, mumps
- Eradicated small pocks and 95% of polio now gone
- Large outbreaks and be prevented if vaccinated
Cons
- DOn’t always work
- Can get a bad reaction- rare
21
Q
What are antibiotics
A
- Medicines that help cure bacterial disease by killing infective bacteria inside body.
- Specific bacteria treated by specific antibiotic
22
Q
What uses to antibiotics and other medicine have in treating disease
A
- -Actually kill or prevent growth the bacteria without killing body cells
- Different for each bacteria
- Cannot kill viruses
23
Q
What is the issue with finding drugs for viruses
A
- Viruses reproduce using body own cells which makes it difficult to kill them with killing your own body
24
Q
What has the use of antibiotics done
A
- Greatly reduced the number of deaths from communicable disease caused by bacteria
25
Q
- `what are the steps in bacteria becoming resistant to antibiotics
A
- Bacteria can mutate-become resistant
- If have infection some bacteria may be resistant to antibiotics
- Only the non-resistant strain survives
- This then reproduces and increase in number-
- Could cause serious infection that antibiotics can treat
e.g MRSA caused wound infections and is resistant to methicillin
26
Q
What can be done to stop down the rate at which resistant strains develop
A
- Doctors can stop overprescribing
- Finish the whole course of antibiotics
27
Q
What are painkillers
A
- Used to treat symptoms, pain, and do not kill pathogens
28
Q
- How can plants be used to create drugs
A
- Plants produce variety of chemicals to defend themselves
- Can be used as drugs to treat humans or relive symptoms
- Some can be extracted from microorganisms
- Most are made by chemists but they are still used today
29
Q
- What examples of plants being used for medication can be seen today
A
- Aspirin- painkiller to lower fever. Found in willow
- Digitalis- Used to treat heart conditions- Found in Foxgloves
30
Q
What was Alexanders Flemming’s discovery
A
- Was clearing out petri dishes containing bacteria
- One of dishes had mould, but area around mould was free of bacteria
- Mould called penicillium notatum was producing substance that killer bacteria
- Penicillin
31
Q
What are the three stages in drug testing- breif
A
- Pre-clinical 1- tissue
- Pre-clinical 2- animals
- Clinical- humans
32
Q
Describe the first stage of drug development
A
- Preclinical-
- Tested on human cells and tissues
- Can’t use humans cells or tissue to test drugs that affect whole or multiple systems
- E.g Blood pressure drug has to be done on whole animal
33
Q
- Describe the second stage in drug development
A
- Pre-clinical 2
- Animals
- Test efficiency, toxicity and dosage
- Law in Britain means new drug has to be tested on two live animals
34
Q
What are efficiency, toxicity and dosage - drugs
A
- Efficiency- Wether it works or not and produces desired effect
- Toxicity- How harmful drug is
- Dosage- Concentration and frequency at which the drug should be given
35
Q
What are contrasting views on Animal testing
A
- Some people say its cruel and wrong.
- Animals don’t get the choice
- Animals are different to humans so its pointless
- Some say its the safest way
- Better for animals to be harmed than humans
36
Q
What is the third stage in Drug development
A
- Clinical testing
- Tested on voluntary, healthy volunteers- side effects
- Starts with very low dose
- optimum dose found with further trials
- If Safe it gets tested on sufferers on illness-
- Goes through peer review and published
37
Q
What is an optimum dose
A
- A dose that produces the greatest effect with the fewest side effect
38
Q
What is a placebo
A
- A substance that is like the drug but does nothing
39
Q
What is the placebo effect
A
- Where someone expects the treatment to work and feel better, even though nothing is happening
40
Q
What is meant by a blind trial
A
- Patients don’t know if they are getting the drug or placebo
- Allows to compare actual results to pleb results
41
Q
What is a double blind trial
A
- Where neither the patient to the doctor know wether or not they have been given the placebo till the end
- stops sub-conscience influencing of testers
