Topic 5 - Health, Diseases And The Development Of Medicines Flashcards
1
Q
How does the World Health Organisation (WHO) define health?
A
“A state of complete physical, mental and social well-being, and not merely the absence of disease or infirmity”
2
Q
What is a communicable disease?
A
A disease that can be spread between individuals.
3
Q
What is a non-communicable disease?
A
A disease that can’t be transmitted between individuals
4
Q
What are pathogens?
A
Organisms such as viruses, bacterial, fungi and protists that cause communicable diseases
5
Q
What is cholera caused by?
A
A bacterium called Vibrio cholerae
6
Q
What are the symptoms of cholera?
A
Diarrhoea
7
Q
How is cholera spread?
A
Contaminated water sources
8
Q
How do you reduce/prevent transmission of cholera?
A
Making sure that people have clean water supplies
9
Q
What is tuberculosis caused by?
A
A bacterium called Mycobacterium tuberculosis
10
Q
What are the symptoms/effects of tuberculosis?
A
Coughing and lung damage
11
Q
How is tuberculosis spread?
A
Through the air when infected individuals cough
12
Q
How do you reduce/prevent transmission of tuberculosis?
A
Infected people should avoid crowded public spaces, practise good hygiene and sleep alone. Their homes should also be well-ventilated
13
Q
What is malaria caused by?
A
A protist
14
Q
What are the effects of malaria?
A
Damage to red blood cells and in sever cases to the liver.
15
Q
How is malaria spread?
A
Mosquitos act as animal vectors (carriers) - they pass on the protist to humans but don’t get the disease themselves.
16
Q
How do you reduce/prevent transmission of malaria?
A
Use of mosquito nets and insect repellent to prevent mosquitos carrying the pathogen from biting people.
17
Q
What are stomach ulcers caused by?
A
A bacterium called Helicobacter pylori
18
Q
What are the symptoms of stomach ulcers?
A
Stomach pain, nausea and vomiting
19
Q
How are stomach ulcers spread?
A
Oral transmission e.g. swallowing contaminated water or food
20
Q
How do you reduce/prevent transmission of stomach ulcers?
A
Having clean water supplies and hygienic living conditions
21
Q
What is ebola caused by?
A
Ebola virus
22
Q
What are the symptoms of ebola?
A
Haemorrhagic fever (a fever with bleeding)
23
Q
How is ebola spread?
A
Bodily fluids
24
Q
How do you reduce/prevent transmission of ebola?
A
Isolating infected individuals and sterilising any area where the virus may be present
25
What is chalara ash dieback caused by?
A fungus that infects ash trees.
26
What are the symptoms of chalara ash dieback?
Leaf loss and bark lesions (wounds)
27
How is chalara ash dieback spread?
Carried through the air by the wind and when diseased ash trees are moved between areas.
28
How do you reduce/prevent transmissions of chalara ash dieback?
Removing young, infected ash tress and replanting with different species and restricting the import or movement of ash trees
29
What is a virus?
They're usually no more than a protein coat around a strand of genetic material
30
How do viruses reproduce?
They have to infect living cells called host cells.
31
What happens in the lytic pathway?
1) The 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
32
What happens in the lysogenic pathway?
1) The 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 (inactive) and no new viruses are made
3) Eventually a trigger (e.g. the presence of a chemical) causes the viral genetic material to leave the genome and enter the lytic pathway
33
What are STIs?
Infections that are spread through sexual contact, including sexual contact
34
What is clamydia?
A kind of bacterium but it behaves in a similar way to a virus because it can only reproduce in host cells
35
How can the spread of chlamydia be reduced?
Wearing a condom when having sex, screening individuals so they can be treated for the infection or avoiding sexual contact
36
What can chlamydia cause?
Infertility in men and women
37
What does HIV stand for?
Human Immunodeficiency Virus
38
What does HIV do?
Kill white blood cells which are important in the immune response
39
What will HIV eventually lead to?
AIDS - Acquired Immune Deficiency Syndrome
40
What happens when someone gets AIDS?
An infected person's immune system deteriorates and eventually fails - because of this, the person becomes very vulnerable to opportunistic infections by other pathogens
41
How is HIV spread?
Bodily fluids
42
How can you prevent the spread of HIV?
Use condoms when having sex, avoid sharing needles
43
What do plants have as a physical barrier?
Most leave and stems have a waxy cuticle?
44
How does having a waxy cuticle help plants defend themselves from disease?
It 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 and water
45
Which cellular structure of a plant is a physical defence?
The cell walls made from cellulose - these form a physical barrier against the pathogens that make it past the waxy cuticle
46
What other type of defence do plants use?
Chemical
47
What do they produce to kill bacterial and fungal pathogens?
Antiseptics
48
What else do plants produce chemicals against?
They produce chemicals to deter pests from feeding on their leaves
49
How can plant chemicals help humans?
Some can be used as drugs to treat human diseases or relieve symptoms
50
Give two plant chemicals that have been used to treat human disease/receive symptoms?
Quinine and aspirin
51
Where does Quinine come from and what does it help?
It comes from the bark of the cinchona tree. For years it was the main treatment of malaria
52
Where does aspirin come from and what is it used for?
It was developed from a chemical found in the bark and leaves of willow trees. It's used to relieve pain and fever.
53
How can plant pathologists identify the kind of pathogen involved in plant diseases?
Analysing the distribution of diseased plants
54
How does the skin act as a physical barrier to the skin?
If it gets damages, blood clots quickly seal cuts to keep microorganisms out
55
How do hairs and mucus act as a physical barrier in the nose?
They trap particles that could contain pathogens
56
Apart from the nose, what else produces mucus?
Cells in the trachea and bronchi
57
Why are cilia in the trachea and bronchi important?
They waft the mucus up to the back of the throat where it can be swallowed
58
What does the stomach produce as a chemical barrier and what does it do?
The stomach produces hydrochloric acid which kills most pathogens swallowed
59
What does the eye produce as a chemical barrier and what does it do?
The eyes produce a chemical called lysozyme (in tears) which kills bacteria on the surface of the eye
60
What happens if pathogens make it into your body?
The immune system kicks in to destroy them
61
What is the most important part of the immune system?
White blood cells
62
How do bacteria make us feel unwell?
Release toxins
63
What are the three ways white blood cells can destroy pathogens?
- Digesting it
- Producing antibodies
- Producing antitoxins
64
What is phagocytosis?
The white blood cell detects the chemicals released by an antigen and moves towards it. It engulfs it and digests it using lysosomes/hydrolytic enzymes.
65
What are T-killer and plasma cells activated by?
Specific T-helper cells
66
What do T-helper cells do?
Activate the specific part of the immune response
67
What do T-killer cells do?
Attack and kill your body's own cells
68
What are antibodies?
Protein molecules produced by white blood cells
69
What happens when a white blood cell releases antibodies?
The antibodies stick to the antigen which triggers the pathogen to be destroyed
70
What does APC stand for?
Antigen presenting cell
71
What do antitoxins do?
Stick to toxin molecules and prevent them from damaging cells
72
What do memory lymphocytes do?
They remain in the body for a long time and 'remember'a specific antigen
73
If someone is immune to something, what does this mean?
Their immune system has the ability to respond quickly to a second infection
74
How is the secondary response different to the first?
It's faster and stronger and it often gets rid of the pathogen before you being to show any symptoms
75
What does immunisation involve?
Injecting dead or inactive pathogens into the body. These are antigenic (carry antigens) so even though they're harmless, your body makes antibodies to destroy them
76
How does immunisation prevent you from getting ill?
The antigens also trigger memory lymphocytes to be made 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
77
What is 'herd immunity'?
Some people are unable to be vaccinated against particular diseases but if everyone else is immunised, fewer people will be able t catch the disease and pass it on meaning it's unlikely the person will catch it
78
What are the advantages of immunisation?
Prevent epidemics
| Virtually wipe out some diseases
79
What are disadvantages of immunisation?
Don't always work
| You can sometimes have a bad reaction
80
What are monoclonal antibodies produced by?
Lots of clones of single b-lymphocytes
81
How are monoclonal antibodies made?
1) Inject mouse with chosen antigen
2) Take b-lymphocytes from the mouse and fuse with tumour cell to make hybridoma
3) Put back into mouse bone marrow
4) Remove after a while and isolate monoclonal antibodies
82
What's the tumour cell used in monoclonal antibodies called?
Myeloma
83
Why are tumour cells used in monoclonal antibodies?
Tumour cells divide lots so can be grown really quickly whereas lymphocytes of their own don't divide very easily.
84
What are the uses of monoclonal antibodies?
- Pregnancy tests
- Targeting cancer cells
- Diagnosing cancer
- Targeting drugs to cancer cells
- Finding blood clots
85
Which hormone is found in the urine of women when they are pregnant?
HCG
86
What is inside a pregnancy testing stick?
1) The bit of the stick that you pee on has some antibodies to the hormone, with blue beads attached
2) The test strip has some more antibodies to the hormone stuck onto it (so they can't move)
87
What happens to the pregnancy testing stick if you're pregnant?
1) The hormone binds to the antibodies on the blue beads
2) The urine moves up the stick, carrying the hormone and the beads
3) The beads and the hormone bind to the antibodies on the test strip
4) So the blue beads get stuck to the strip turning it blue
88
What happens to the pregnancy testing stick if you're not pregnant?
The urine still moves up the stick, carrying the blue beads. However, theres nothing to stick the blue beads onto the test strip so it doesn't go blue
89
What is a tumour marker?
Proteins on the cell membranes of cancer cells that aren't found on normal body cells
90
How can monoclonal antibodies be used to diagnose cancer?
1) Antibodies are labelled with a radioactive element and given to a patient through a drip. They go into the blood and are carried around the body
2) When the antibodies come into contact with the cancer cells they bind to the tumour markers
3) A picture of the patients body is taken using a camera that detects radioactivity. Cancer cells show up as a bright spot
91
What are doctors able to see when the monoclonal antibodies are used to detect cancer?
They can see where the cancer is, what size it is and find out if it's spreading
92
How can monoclonal antibodies be used to target cancer cells?
An anti-cancer drug is attached to monoclonal antibodies which are given to the patient through a drip. The antibodies target the specific cancer cells because they only bind to the tumour markers
93
Why is using the anti-cancer drug and monoclonal antibodies better than other cancer treatments?
The drug kills the cancer cells but doesn't damage the normal body cells around it since the antibodies only target the cancer cells. However, other cancer treatments like drugs and radiotherapy can affect normal body cells as well as killing the cancer cells meaning they have more side-effects than the anti-body based drugs do
94
What happens when blood clots and what is formed?
Proteins in the blood join together to form a solid mesh
95
How can monoclonal antibodies be used to find blood clots?
Monoclonal antibodies have been developed to the proteins in the blood. If you attach a radioactive element to these antibodies, inject them into the body and take a picture using a camera that picks up radiation, the blood clot will show up as a bright spot.
96
Why is using monoclonal antibodies to find blood clots useful?
You can easily find potentially harmful blood clots and then get rid of it before it harms the patient
97
How do antibiotics work (with an example)?
Antibiotics work by inhibiting processes in bacterial cells, but not in the host organism. For example, some antibiotics inhibit the building of bacterial cell walls - this prevents the bacteria from dividing and eventually kills them but has no effect on the human host
98
What don't antibiotics destroy and why?
Antibiotics dont destroy viruses because viruses reproduce using your body cells making it difficult to develop drugs that destroy just the virus without killing the body's cell
99
How was penicillin discovered?
Alexander Flemming discovered it when he was clearing out Petri dishes containing bacteria. He noticed that some of the dishes had mould on it and the area around the mould was free of bacteria. The mould was producing penicillin, which was killing the bacteria
100
What happens in the first stage of preclinical testing?
Drugs are first tested on human cells and tissues in the lab. However you can't use human cells and tissues to test drugs that affect whole or multiple body systems e.g. a drug for blood pressure must be tested on a whole animal
101
What is the second step of preclinical testing?
The next step is to test the drug on live animals. This is to test that the drug works, to find out how toxic it is and to find out the best dosage
102
What is a drug tested on in a clinical trial?
Human volunteers
103
What is the first stage of clinical trials?
The drug is tested on health volunteers to make sure it doesn't have any harmful side effects when the body is working normally
104
What's the second stage of clinical trials?
If results on health volunteers are good, the drugs new tested on people suffering from the illness. The optimum dose is found.
105
What is the optimum dose?
The dose of the drug that is the most effective and has the fewest side effects
106
What is a placebo?
A substance that looks like the drug being tested but doesn't do anything e.g. a sugar pill
107
What is the placebo effect?
When the patient expects the treatment to work and therefore feels better, even though the treatment isn't doing anything
108
What is the third stage of clinical trials?
Patients are randomly put into two groups. One is given the new drug and the other is given a placebo. This is to allow for the placebo effect
109
What is a double-bling trial and why is it used?
Neither the patient or the doctor knows whether they're getting the drug or a placebo until the results have been gathered. This is so the doctors monitoring the patient and analysing the results are subconsciously influenced by their knowledge.
110
How is bacteria grown in the lab?
Bacteria are cultured (grown) in a growth medium, which contains the carbohydrates, minerals, proteins and vitamins they need to grow
111
What are the two growth mediums that can be used?
Nutrient broth solution or agar jelly
112
What will bacteria grown on agar 'plates' form?
Visible colonies on the surface of the jelly or will spread out to give an even covering
113
How do you make an agar plate?
Hot agar jelly is poured into shallow round plastic dishes called Petri dishes. When the jelly's cooled down and set, wire loops can be used to transfer microorganisms to the agar jelly.
114
What is an alternative method of transferring the microorganisms to the agar plate?
A sterile dropping pipette and spreader can be used to get an even covering of bacteria. The microorganisms then multiply
115
Why are cultures of microorganisms kept at about 25℃ in school labs?
Harmful pathogens are less likely to grow at this temperature
116
Why might scientists culture microorganisms at higher temperature outside of schools?
Provide optimum temperatures for growth
117
What is the difference between antibiotics and antiseptics?
Antibiotics kill bacteria inside of the body whereas antiseptics kill bacteria outside of the body
118
What are the steps of investigating the effects of antibiotics?
1) Place paper discs soaked in different types of antibiotics of the agar plate that has an even covering of bacteria, leave some spaces between the discs
2) The antibiotic should diffuse into the agar jelly. Antibiotic-resistant bacteria will continue to grow around the paper discs but non-resistant strains will die leaf the inhibition zone
3) Use a control. This is a paper disc that hasn't been soaked in an antibiotic
4) Leave plate for 48 hours at 25℃
119
What is the inhibition zone?
A clear area that will be left where the bacteria have died
120
Why do you need the unsealed paper disc as a control whilst investigating the effects of antibiotics?
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 (and not something weird like the paper, for example)
121
Why should you use aseptic techniques when doing this method?
Contamination by unwanted microorganisms will affect your results and can potentially result in the growth of pathogens. Using aseptic techniques helps to avoid this
122
What aseptic techniques should be used when investigating the effects of antiseptics?
- Petri dishes and growth medium must be sterilised before use
- Wire loop should be sterilised before transferring bacteria
- Liquid bacterial cultures should be kept in a culture vial with a lid
- Petri dish should be covered with a lid and lightly taped
- Petri dish should be stored upside-down
123
Why does the Petri dish need to be stored upside-down?
To stop drop of condensation falling onto the agar
124
How can Petri dishes and growth mediums be sterilised?
Placing them in an autoclave which uses steam at a high pressure and temperature to kill any microorganisms present
125
How can the wire loop be sterilised?
Passing it through a hot flame
126
Why are lids needed on the liquid bacterial cultures and Petri dishes?
To stop other microbes and microorganisms from the air from getting in
127
How can you compare the effectiveness of different antibiotics, antiseptics or plant extracts?
Looking at the relative sizes of the inhibition zones e.g. the larger the inhibition zone, the more bacteria killed and therefore the more effective the antibiotic is against the bacteria
128
How can you measure the area of an inhibition zone?
Area = 𝞹r²
129
What are risk factors?
Things that are linked to an increase in the likelihood that a person will develop a certain disease during their lifetime
130
Name some unavoidable risk factors?
Age, gender etc.
131
What is cardiovascular disease?
Any disease associated with the heart of blood vessels e.g. heart attack or stroke
132
What are the major risk factors associated with cardiovascular disease?
Smoking, drinking too much alcohol, lack of exercise and diet in high saturated fat
133
How does smoking increase the risk of cardiovascular disease?
Nicotine in cigarette smoke increases heart rate, which increases blood pressure. 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 heart attack or stroke
Smoking also increases the risk of blood clots forming in the arteries which can restrict or block blood flow leading to heart attack or stroke
134
What are risk factors for obesity?
Not getting enough exercise of having a diet high in fat or sugar
135
What is drinking too much alcohol a risk factor for and why?
Liver diseases like liver cirrhosis. This is because the 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
136
Why are non-communicable diseases a problem for the economy of a country?
They're mostly on a national level because the NHS provides the resources for the treatment of patients all over the UK. Sometimes people suffering from non-communicable diseases may not be able to work, effecting the country's economy. Moreover, non-communicable diseases are very common
137
What is body mass index (BMI)?
Used as a guide to help decide whether someone is underweight, normal, overweight or obese
138
How is BMI calculated?
Weight (kg) ÷ (Height (m))²
139
What causes a high BMI?
If you eat a high fat, high sugar diet and you don't do enough exercise, you're likely to take in more energy than you use. The excess energy is stored as fat so you're more likely to have a high BMI
140
Why isn't BMI always a reliable measure of obesity?
For example, athletes have lots of muscle which weighs more than fat so that can come out with a high BMI even though they're not overweight
141
How do you calculate waist-to-hip-ratio?
Waist circumference ÷ Hip circumference
142
What ratio for men and women suggests you're carrying too much weight around your middle?
Men - Above 1.0
| Women - Above 0.85
143
What is abdominal obesity and what are the risks of it?
It's when you're carrying too much weight around your middle. It puts you at risk of developing obesity-related health problems such as type 2 diabetes.
144
What are arteries?
Blood vessels that carry blood away from the heart
145
What is cholesterol?
A fatty substance that the body need to make new things like cell membranes
146
What can too much cholesterol cause?
It can cause fatty deposits to build up in the arteries, restricting blood flow
147
Where do deposits occur?
In areas where the artery wall has been damaged e.g. by high blood pressure
148
What can fatty deposits also trigger?
Blood clot formation which can block the blood flow completely causing a heart attack (blockage in heart) or stroke (blockage in brain) due to muscle being deprived of oxygen
149
What lifestyle changes can be made to treat or reduce the risk of CVD?
- Eating a healthy, balanced diet which is low in saturated fat
- Exercising regularly
- Losing weight
- Stop smoking
150
Why are lifestyle changes often recommended first?
Do't have any downsides
151
What do statins do?
Reduce the amount of cholesterol in the bloodstream. This slows down the rate at which fatty deposits form - reducing the risks of heart attacks and strokes
152
Disadvantages of statins?
Side effects like aching muscles or liver damage
153
What do anticoagulants do?
Drugs which make blood clots less likely to form
154
Disadvantage of anticoagulant?
Can cause excessive bleeding if the person is hurt in an accident
155
What do antihypertensives do?
Reduce blood pressure helping to prevent damage to blood vessels and so reduces the risk of fatty deposits forming.
156
Disadvantage of antihypertensives?
Side effects like headaches and fainting
157
What are the three surgical procedures sometime necessary to repair damage?
- Stents
- Coronary bypass surgery
- Donor heart
158
What are stents and what do they do?
Tubes inserted inside arteries. They keep them open making sure blood can pass through to the heart muscle, lowering risk of heart attack
159
Disadvantages of stents?
Overtime the artery can narrow again as stents can irritate the artery and make scare tissue grow
Patient has to take drugs to stop blood from clotting on the stent
160
What is 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
161
What are disadvantages of having your heart replaced by a donor heart?
Heart does not always start pumping properly
Drugs have to be taken to stop the body rejecting it, these drugs have side effects like making you more vulnerable to certain infections
Heart surgery is a major procedure and there is a risk of bleeding, clots and infection
