Topic 5 - Health, Disease And Medicines Flashcards
(80 cards)
1
Q
Health definition
A
- A state of complete physical, mental and social well being, and not merely the absence of disease or infirmity.
2
Q
Communicable disease definition
A
Diseases that can be spread between individuals
3
Q
Non communicable disease definition
A
Diseases that cannot be transmitted between individuals.
4
Q
Define a pathogen:
A
Organisms such as viruses, bacteria, fungi and protists that cause communicable diseases.
5
Q
Example of a viral disease, symptoms, spread and treatment
A
- Ebola
- Causes haemorrhaging fever (fever with bleeding)
- Spread via bodily fluids
- Isolate infected individuals and sterilise any areas where the virus may be present.
6
Q
Example of a fungal disease, symptoms, spread and treatment
A
- Chalara ash dieback
- Leaf loss, bark lesions (wounds)
- Carried through air by wind. Can spread when diseased ash trees are moved between areas.
- Remove young, infected trees and replant with different species or restrict the import/movement of ash trees.
7
Q
Example of a protist disease, symptoms, spread and treatment
A
- Malaria
- Damage to red blood cells, liver
- Mosquitoes act as animal vectors (pass on the protist to humans but don’t get the disease themselves).
- Mosquito nets and insect repellent can be used to prevent mosquitoes biting people.
8
Q
Cholera - symptoms, spread and treatment
A
- Caused by a bacterium
- Causes diarrhoea
- Spreads via contaminated water sources
- Make sure people have access to clean water supplies.
9
Q
Tuberculosis - symptoms, spread and treatment
A
- Caused by a bacterium
- Causes coughing and lung damage
- Spread through air when infected people cough
- Infected people should avoid crowded public spaces, practise good hygiene and sleep alone. Have a well-ventilated home.
10
Q
Stomach Ulcers - symptoms, spread and treatment
A
- Caused by a bacterium
- Stomach pain, nausea, vomiting
- Spread through oral transmission e.g swallowing contaminated water/food
- Have clean water supplies and hygienic living conditions.
11
Q
STI definition -
A
Sexually Transmitted Infections are infections that spread through sexual contact, including sexual intercourse.
12
Q
Chlamydia - symptoms, spread and treatment
A
- Bacterium
- Doesn’t always cause symptoms, can result in infertility
- Wear a condom, screen individuals so they can be treated or avoid sexual contact.
13
Q
HIV - symptoms, spread and treatment
A
- Caused by a virus
- Kills white blood cells, which are important in the immune response
- Leads to AIDS
- This is when the immune system deteriorates and fails so because of this, the person becomes vulnerable to infections by other pathogens.
- Spread via infected bodily fluids.
- Use a condom, don’t share needles, take medication to reduce the risk of passing the virus on during sex. Screening and proper treatment are important.
14
Q
Lytic Pathway of a virus:
A
1) - Virus attaches itself to a specific host cell and injects its genetic material into the cell.
2) - The virus uses proteins and enzymes in the host cell to replicate its genetic material and produce the components of new viruses.
3) - The viral components assemble.
4) - The host cell splits open, releasing the new viruses, which infect more cells.
15
Q
Lysogenic Pathway:
A
1) - Injected genetic material is incorporated into the genome of the host cell.
2) - The viral genetic material gets replicated along with the host DNA every time the host cell divides - but the virus is dormant and no new viruses are made.
3) - Eventually a trigger (e.g the presence of a chemical) causes the genetic material to leave the genome and enter the lytic pathway.
16
Q
Waxy Cuticle as a Physical Defence:
A
- Plant leaves and stems have a waxy cuticle, which provides a barrier to stop pathogens entering them or pests from damaging them.
- It may also stop water collecting on the leaf, which could reduce the risk of infection by pathogens that are transferred between plants in water.
17
Q
Cell Wall as a Physical Defence:
A
- Cell walls made from cellulose
- These form a physical barrier against pathogens that make it past the waxy cuticle.
18
Q
Plant Chemical Defences:
A
- Produce chemicals that help prevent damage to the plant.
- Antiseptics for example kill bacterial and fungal pathogens.
- Chemicals can deter pests e.g insects from feeding on their leaves.
19
Q
How can plant chemical defences be used as drugs to treat human disease or relieve symptoms?
A
- Quinine comes from the bark of the cinchona tree. It was a main treatment for malaria.
- Aspirin is used to relieve pain and fever. It was developed from a chemical found in the bark and leaves of willow trees.
20
Q
How can plant diseases be detected in the field?
A
1) - Detected by observations. Plant pathologists recognise the symptoms e.g galls (abnormal growths) might indicate crown gall disease in apples and fruit trees.
2) - Plants may show symptoms of a disease due to environmental causes, like a nutrient deficiency. By changing the environmental conditions (e.g adding nutrients to the soil) and observing any change in the plant’s symptoms, you can determine whether a plant is diseased or if the symptoms were due to something else.
3) - Different pathogens are spread in different ways - so plant pathologists can analyse the distribution of diseased plants to identify the kind of pathogen involved.
21
Q
How does detecting antigens in the lab help to identify plant diseases?
A
1) - Pathogens have unique molecules on their surface called antigens.
2) - Antigens from a particular pathogen will be present in a plant infected with that pathogen and can be detected in a sample of plant tissue (using monoclonal antibodies).
3) - The detection of an antigen unique to a particular pathogen allows that pathogen to be identifies and the disease diagnosed.
22
Q
How does detecting DNA in the lab help to identify plant diseases?
A
1) - If a plant is infected with a pathogen, the pathogen’s DNA will be present in the plant’s tissues.
2) - Scientists have techniques that allow them to detect even small amounts of pathogen DNA in a sample of plant tissue, allowing them to identify the particular pathogen that is present.
23
Q
Human Physical Barriers:
A
1) - The skin acts as a barrier to pathogens and if it gets damaged, blood clots quickly seal cuts and keep microorganisms out.
2) - Hairs and mucus in your nose trap particles that could contain pathogens.
3) - Cells in your trachea and bronchi produce mucus, which trap pathogens. Other cells that line the trachea and bronchi have cilia. These are hair-like structures which waft the mucus up to the back of the throat where it can be swallowed.
24
Q
Chemical Barriers in Humans:
A
1) - The stomach produces hydrochloride acid which kills most pathogens that are swallowed.
2) - The eyes produce a chemical called lysozyme (in tears) which kills bacteria on the surface of the eye.
25
How does the specific immune response work?
1) - Every pathogen has unique molecules on its surface called antigens.
2) - When your B-lymphocytes (type of white blood cell) come across an antigen on a pathogen, they start to produce proteins called antibodies.
3) - Antibodies bind to the new invading pathogen, so it can be found and destroyed by other white blood cells. The antibodies produced are specific to that pathogen (they won’t lock on to any other pathogens).
4) - The antibodies are then produced rapidly and flow all around the body to find all similar pathogens.
26
Secondary Immune Response (6 marks):
1) - When a pathogen enters the body for the first time, the response is slow because there aren’t many B-lymphocytes that can make the antibody to lock on to the antigen.
2) - Eventually, the body will produce enough of the right antibody to overcome the infection. Meanwhile, the infected person will show symptoms of the disease.
3) - As well as antibodies, memory lymphocytes are also produced in response to a foreign antigen. Memory lymphocytes remain in the body for a long time, and remember a specific antigen.
4) - The person is now immune - their immune system has the ability to respond quickly to a second infection.
5) - If the same pathogen enters the body again, there are more cells that will recognise it and produce antibodies against it. This secondary immune response is faster and stronger.
6) - The secondary response often gets rid of the pathogen before you begin to show nay symptoms.
27
How can immunisation stop you getting infections?
1) - To make it less likely that you’ll get ill, you can immunised against some diseases like measles.
2) - Immunisation usually involves injecting dead or inactive pathogens into the body. These are antigenic so even though they’re harmless, your body makes antibodies to help destroy them.
3) - The antigens also trigger the production of memory lymphocytes.
4) - So, if live pathogens of the same type get into the body, there will already be memory lymphocytes that can cause a fast secondary immune response. This means that you’re less likely to get the disease.
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Pros of Immunisation:
1) - Epidemics can be prevented if a large percentage of the population are immunised. Even the people who aren’t immunised are unlikely to catch the disease because there are fewer people able to pass it on - this is known as herd immunity.
2) - Some diseases e.g smallpox have been virtually wiped out by immunisation programmes.
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Cons of immunisation:
1) - Immunisation doesn’t always work - sometimes it doesn’t give you immunity.
2) - You can sometimes have bad reaction to a vaccine (e.g swelling, fever, seizures). Bad reactions are very rare.
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What are antibodies produced by?
B-lymphocytes which are a type of white blood cell.
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What are monoclonal antibodies produced from?
- Lots of clones of a single B-lymphocyte.
- This means all the antibodies are identical and will only target one specific protein antigen.
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How easily do lymphocytes divide?
***Not*** very easily.
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How easily do tumour cells divide?
***Lots***, so they can be grown really easily.
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Process of making monoclonal antibodies:
- Fuse a mouse B-Lymphocyte with a tumour cell called a myeloma cell to create a cell called a hybridoma.
- Hybridomas can be cloned to get lots of identical cells that can divide really quickly to produce the same antibodies (monoclonal).
- These can be collected and purified.
35
What is a hybridoma?
Fusion of a mouse B-Lymphocyte with a tumour cell called a myeloma cell.
36
Advantage of having monoclonal antibodies:
- They can bind to anything you want e.g an antigen that’s only found on the surface of one type of cell.
- They’re useful because they will only bind to this molecule - this means you can use them to target a specific cell or chemical in the body.
37
HCG:
A hormone found in the urine of only pregnant women.
38
How do pregnancy testing kits work?
1) - The bit of the stick you wee on has antibodies to the hormone, with blue beads attached.
2) - The test strip has more antibodies to the hormone stuck onto it (so that they can’t move).
39
If you’re pregnant and you wee on the stick, then:
- The hormone binds to the antibodies on the blue beads.
- The urine moves up the stick, carrying the hormone and the beads.
- The beads and hormone bind to the antibodies on the strip.
- So, the blue beads get stuck on the strip, turning it blue.
40
If you’re not pregnant and you wee on the stick, then:
- The urine still moves up the stick, carrying the blue beads.
- But, there’s nothing to stick the blue beads onto the test strip, so it doesn’t go blue.
41
Monoclonal Antibodies to find blood clots:
1) - When blood clots, proteins in the blood join together to form a solid mesh.
2) - Monoclonal antibodies have been developed that bind to these proteins.
3) - You can attach a radioactive element to these antibodies.
4) - Then, if you inject them into the body and take a picture using a camera that picks up the radiation, that picture will have a bright spot where there is a blood clot.
5) - This is useful because you can easily found a potentially harmful blood clot and get rid of it.
42
Monoclonal Antibodies to ***target*** cancer cells:
1) - Cancer cells have proteins on their cell membranes that aren’t found on normal body cells. They’re called tumour markers.
2) - In the lab, you can make monoclonal antibodies that will bind to these tumour markers. They can be used to help diagnose and treat cancer.
43
Define tumour markers:
- Proteins on cancer cell membranes that aren’t found on normal body cells.
44
How can monoclonal antibodies be used to **diagnose*** cancer?
1) - The antibodies are labelled with a radioactive element.
2) - The labelled antibodies are given to a patient through a drip. They go into the blood and are carried around the body.
3) - When the antibodies come into contact with the cancer cells they bind to the tumour markers.
4) - A picture of the patient’s body is taken using a camera that detects radioactivity. Anywhere there are cancer cells will show up as a bright spot.
5) - Doctors can see exactly where and what the cancer is.
45
How can monoclonal antibodies be used to target drugs to cancer cells?
1) - An anti-cancer drug is attached to monoclonal antibodies.
2) - The antibodies are given to a patient through a drip.
3) - The antibodies target specific cells because they only bind to the tumour markers.
4) - Therefore, lower side effects.
46
Why can antibiotics only be used to treat bacterial infections?
- Because they inhibit cell processes in the bacterium but not the host organism.
47
Stages of drug development:
1) - Discovery
2) - Development
3) - Preclinical Trials
4) - Clinical Trials
5) - Release after approval
48
Preclinical testing:
1) - Drugs are first tested on human cells and tissues in the lab.
2) - Test on live animals to test the drug works, to find out how toxic it is and to find the best dosage.
49
Clinical testing:
1) - Human volunteers (firstly healthy to ensure no unwanted side effects)
2) - Unhealthy volunteers. The optimum dose is found (most effective, fewest side effects).
3) - Patients are put into two groups. One is given the drug, the other is given a placebo to check the treatment is actually working.
4) - These trials are blind and sometimes double-blind (doctor and patient don’t know).
50
Define optimum dose
Dose with the most effectiveness and the fewest side effects
51
Define double-blind:
Where the doctor and the patient don’t know if the patient is taking a placebo or not in a clinical trial.
52
Method of agar jelly ***core practical***:
1) - Place paper discs soaked in different types of antibiotics on an agar plate that has an even covering of bacteria. Leave some space between the discs.
2) - The antibiotic should diffuse into the agar jelly. Antibiotic resistant bacteria will continue to grow on the agar around the paper discs, but non-resistant strains will die. A clear area will be left where the bacteria have died - this is called the inhibition zone.
3) - Leave the plate for 48 hours at 25C.
4) - The more effective the antibiotic, the larger the zone of inhibition.
53
Zone of inhibition -
A clear area left where the bacteria have died.
54
What is your control in the agar jelly ***core practical***?
- A paper disc that has not been soaked in an antibiotic.
- You can then be sure that any difference between the growth of the bacteria around the control disc and around one of the antibiotic discs is due to the effect of the antibiotic alone.
55
Why must the Petri dish and growth medium be sterilised before use?
Sterilise the Petri dish and growth medium before use by placing them into a machine called an autoclave which uses steam at high pressures and temperatures to kill any microorganisms present.
56
Why sterilise an inoculating loop?
- Pass it through a hot flame so unwanted microorganisms are killed
57
How to keep liquid bacterial cultures sterilised?
- Keep them in a culture vial with a lid.
- Only briefly remove the lid when transferring bacteria, to prevent other microbes getting in.
58
Why should the Petri dish have a lid on?
- To stop microorganisms from the air getting in
59
Why store the Petri dish upside down?
- To stop drops of condensation falling onto the agar.
60
Why is smoking a risk factor?
1) - Nicotine increases heart rate, which increases blood pressure.
2) - High blood pressure damages artery walls, which contributes to the build up of fatty deposits in the arteries. These deposits restrict blood flow and increase the risk of a heart attack or stroke.
3) - Smoking also increases the risk of blood clots forming in arteries, which can restrict or block blood flow, leading to a heart attack or stroke.
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Malnutrition:
- A diet with too many or too few nutrients.
- Can get scurvy as it is a vitamin c deficiency.
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Risk factors for obesity:
- Not getting enough exercise
- Having a diet high in fat and sugar.
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Why is alcohol a risk factor?
- Can get liver disease as alcohol is broken down by enzymes in the liver and some of the products are toxic.
- Drinking too much over a long period of time can cause permanent liver damage.
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CVD risk factors
- Drinking lots of alcohol
- Lack of exercise
- High saturated fat intake
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Effects of Non-Communicable Diseases:
1) - Pressure on resources like money, beds and staff at hospitals.
2) - A reduction in the amount of people able to work
3) - Reduce development of a country e.g CVD is number one cause of death worldwide.
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What is obese BMI?
30+ for white people
27.5+ for BAME people
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Unhealthy waist:hip ratio
1+ for males
0.85+ for females
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What are arteries?
- Blood vessels that carry blood away from the heart.
69
What is cholesterol?
- Fatty substance that the body needs to make things like cell membranes.
- Too much cholesterol in the blood can cause fatty deposits to build up in the arteries, restricting blood flow.
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Where do fatty deposits occur?
- In areas where the artery wall has been damaged e.g by high blood pressure.
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What can fatty deposits trigger?
- Blood clots to form, which can block blood flow completely.
- If this happens in an artery supplying the heart, the heart will be deprived of oxygen leading to a heart attack.
- A blockage in the brain deprives it of oxygen and can cause a stroke.
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Lifestyle changes to treat CVD:
1) - Eat a balanced, healthy diet which is low in saturated fat.
2) - Exercise regularly to lose weight.
3) - Stop smoking.
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What do statins do?
- They reduce the amount of cholesterol in the bloodstream.
- This slows down the rate at which fatty deposits form, reducing the risk of heart attacks and strokes.
- However, they can cause negative side effects e.g aching muscles or serious ones like liver damage.
74
What do anticoagulants do?
- Drugs which make blood clots less likely to form.
- This can cause excessive bleeding if the person is hurt in an accident.
75
What do antihypertensives do?
- Reduce blood pressure.
- Helps to prevent damage to blood vessels and so reduces the risk of fatty deposits forming.
- Can cause headaches and fainting.
76
What do stents do?
- Tubes that are inserted through arteries.
- They keep arteries open, making sure blood can pass through to the heart muscles, lowering the risk of a heart attack.
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Disadvantages of stents:
- Over time, the artery can narrow again as stents can irritate the artery and make scar tissue grow.
- The patient has to take drugs to stop blood clotting on the stent.
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Coronary Bypass Surgery:
- If part of a blood vessel is blocked, a piece of healthy vessel taken from elsewhere can be used to bypass the blocked section.
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Donor Heart - what is it?
- Whole heart replaced with a donor heart.
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Side effects/disadvantages of donor heart?
- Risk of bleeding, clots, infection from major heart surgery.
- The heart does not always start pumping properly.
- Drugs have to be taken to stop the body rejecting it.
- These drugs can have side effects like making you more vulnerable to infections.
