Topic 5 - health, disease and the development of medicines Flashcards
1
Q
Define health
A
A state of complete physical, mental and social well-being
2
Q
Define disease
A
A disorder of the body or mind that negatively affects an individual’s health
3
Q
What are two types of disease?
A
Communicable
Non-communicable
4
Q
What is a communicable disease?
A
A disease that is passes directly between individuals
Caused by a pathogen
5
Q
Define pathogen
A
A disease-causing organism
6
Q
What is a non-communicable disease?
A
A disease that cannot be transmitted between individuals
7
Q
What is a symptom?
A
A change experienced by an organism that indicated disease
8
Q
Why does having an illness make an individual more likely to contract another disease?
A
A disease may weaken an individual’s immune system making them increasingly susceptible to other infections
9
Q
Describe cholera
A
Spread by drinking water or washing in water that has been contaminated
Symptoms: vomiting, diarrhoea
Caused by vibrio cholera bacterium
10
Q
How can the incidence of cholera be reduced?
A
Access to clean water
Improved sanitation
11
Q
Describe tuberculosis
A
Caused by mycobacterium tuberculosis bacterium
Is airborne bacteria spread by droplet infection
Symptoms: lung damage, chesty cough, wheezing
12
Q
How can the transmission of TB be reduced?
A
Improved hygiene
Infected individuals avoid crowded areas
Increased ventilation in individual’s home
13
Q
Describe chalaza ash dieback
A
Caused by a fungus that infects ash trees
Spread via airborne stored which are carried by the wind
Causes dark lesions on bark and blackened leaves which wilt and eventually die
14
Q
How can the transmission of chalaza ash dieback disease be reduced?
A
Control the movement of ash trees
Kill infected plants
Replant with different species
15
Q
Describe malaria
A
Caused by plasmodium protist
Spread by mosquito vectors
Flu-like symptoms, damage to red blood cells, liver damage
16
Q
How can the incidence of malaria be reduced?
A
Mosquito nets
Insect repellant
Cover arms and legs
17
Q
Describe stomach ulcers
A
Caused by helicobacter pylori bacterium
Transmitted orally by eating infected foods or drinking infected water
Symptoms: stomach pain, vomiting, nausea
18
Q
How can the transmission of helicobacter pylori be reduced?
A
Access to clean water
Improved hygiene
Improved sanitation
19
Q
Describe Ebola
A
Caused by Ebola virus
Spread by direct contact with infected body fluids
Symptoms: fever, diarrhoea, vomiting, internal bleeding
20
Q
How can the transmission of Ebola be reduced?
A
Improved hygiene
Isolating infected individuals
Sterilisation of outbreak areas
21
Q
Describe simply how viruses cause disease
A
They enter host cells and replicate inside of them. The host cells rupture, releasing new viruses
22
Q
How do viruses differ from other microorganisms?
A
They are not living
They do not reproduce and can only replicate inside a host cell
23
Q
By what two pathways do viruses replicate inside living cells?
A
Lytic pathway
Lysogenic pathway
24
Q
Describe the lytic pathway
A
Virus binds to receptors on host cell
Injects its DNA into host cell and replicated its DNA using host cell machinery
New viral structures are produced and assembled
Host cell ruptures, releasing new viruses
25
Describe the lysogenic pathway
Virus binds to receptors on host cell
Viral DNA injected into host cell and becomes integrated into host cell genome
Viral DNA replicated each time the host cell divides but the cell remains normal
Trigger causes the activation of viral DNA, it enters the lytic pathway
26
Describe HIV
Caused by human immunodeficiency virus
Spread by direct contact with infected bodily fluids
Destroys white blood cells making the individual immunodeficient and increasingly susceptible to other diseases, leads to aids
27
How can the spread of HIV be reduced?
Protected sex
Needle exchange
Screening blood
Deterring infected mothers from breastfeeding
28
Describe chlamydia
Caused by chlamydia bacterium
Spread through sexual contact
Can result in infertility
29
How can the transmission of chlamydia be reduced?
Protected sex
| Screening
30
Describe the physical defence system within plants
Waterproof waxy cuticle
| Cellulose cell wall
31
Give examples of chemical barriers in plants
Secretion of toxins to reduce damage by pests
| Production of antibacterial chemicals that kill bacterial pathogens
32
Why are chemicals produced by plants useful?
They produce physiological effects on the body so can be used in medicines
33
Give an example of a medicine derived from plants
Aspirin - painkiller, bark/Leaves of salix alba
34
Why are plant defence systems important?
Important in maintaining human food security
| Are producers so all organisms higher up the food chains rely on their survival
35
How can plant diseases be detected and identified in the field.
Observation of symptoms
Analysis of distribution
Changing environmental conditions
36
Why is it difficult to identify a disease using symptoms alone?
Many diseases may have similar symptoms
37
How can plant diseases be detected and identified in the lab?
Detection of foreign antigens in a sample of plant tissue
| Analysis of DNA to identify and pathogen DNA in a tissue sample
38
What is a non-specific defence?
Always present
Same for all organisms
Prevents pathogens from entering the body
39
Give three examples of the body’s physical defence system
Skin
Blood clotting
Respiratory tract
40
Give two examples of the body’s chemical defence system
Tears (lysozyme)
| Hydrochloric acid
41
What is the immune system?
The body’s defence against pathogens once they have entered the body
Aims to prevent or minimise disease caused by pathogens
42
How do white blood cells detect pathogens in the body?
They have unique antigens on their surface which are detected by specialised receptors on white blood cells
43
How does the immune system destroy pathogens?
Lymphocytes produce antibodies in response to a particular antigen
Each antibody is specific to an antigen and binds to it
Antibodies clump pathogens together, disabling them so that they can be killed by other white blood cells
44
What are memory lymphocytes?
White blood cells produced in response to a foreign antigen that remains in the body after a pathogen is destroyed to provide immunity
45
Compare primary and secondary immune responses
The secondary response produces antibodies more rapidly and in higher concentrations than the primary so the pathogen is destroyed before it can cause symptoms
46
What is a vaccination?
Deliberate exposure of an individual to foreign antigens
Triggers an immune response and provides immunity
The individual does not contract the disease that they are being immunised against
47
Describe the components of a vaccine
Dead, weakened or inactivated pathogens with their surface antigens still present
48
What are the benefits of vaccinations?
Herd immunity
| Helps to prevent epidemics and pandemics
49
What are the drawbacks of vaccinations?
Not guaranteed to work
May cause an adverse reaction
Programmes are costly
High mutation rate of viruses changes the structure of antigens, making the vaccine ineffective
50
What is an antibiotic?
A substance that kills or inhibits growth of bacteria
51
Describe how ‘target’ molecules for new medicines can be identified
The alleles themselves or the proteins that they code can be used as a target
Comparisons of the genomes of unaffected individuals and those who are affected by a disease to identify potential disease-causing alleles
52
Outline the stages of drug development
Screening for potential drugs
Preclinical trials
Clinical trials
Approved by a medicinal agency
53
Describe the process of screening
Uses a machine to test large libraries of chemical substances
Enables identification of pre-existing chemicals which may affect the target molecule
Chemicals may be altered, allowing scientists to produce a drug that reacts with target molecules in a specific way
54
What do preclinical trials involve?
Drug tested on cultured human cells and using computer models to determine its toxicity and efficiency
Drug then tested on live animals to establish a safe dose for humans and observe and side effects
55
What happens during comical testing?
The drug is first tested on healthy human volunteers to ensure that it is safe to use and has no unwanted effects on the body
Drug then tested on patients with the disease to determine its efficacy
Dosage is slowly increased until an upper limit is established
Optimum dosage is found
56
What are placebos?
A substance that appears just like the real drug but has no effect on the recipient
57
What is a blind trial?
Where the participants don’t know whether they are receiving the new drug or the placebo
Prevents the patient’s bias affecting the results
58
What is a double blind trial?
Neither the participants nor the doctors know who is receiving the new drug or the placebo
Prevents bias from doctors when analysing results
59
What is the problem associated with using placebos on patients with a disease?
It might not be ethical to prescribe a sick patient with a placebo knowing that it will do nothing to help their condition
60
What are monoclonal antibodies?
Antibodies that are clones from one parent cell
| Specific to one type of antigen
61
Describe how monoclonal antibodies are produced
Specific antigen injected into an animal
Lymphocytes producing complementary antibodies extracted
Lymphocytes fuse with myeloma cells to form hybridoma cells
Hybridoma cells cultured
Monoclonal antibodies collected and purified
62
What are myeloma cells?
Type of tumour cell
63
Outline the uses of monoclonal antibodies
Detection of pathogens
Location of cancer cells and blood clots
Treatment of cancer
Used in pregnancy test kits
64
What do pregnancy kits test for?
HCG in urine
65
What does a pregnancy test consist of?
A stick containing monoclonal antibodies specific to hCG
66
Describe what happens to the test stick if the woman is pregnant
hCG in urine binds to monoclonal antibodies attached to a blue bead
Monoclonal antibodies with hCG diffuse up dipstick
Monoclonal antibodies fixed to the stick bind to hCG
Blue line forms
67
Describe what happens to the test stick if a woman if not pregnant
No blue line is formed
68
What is the advantage of using monoclonal antibodies to test for pathogens?
Specific to one particular antigen
Very accurate
Quick results
69
Why can monoclonal antibodies be used to target cancer cells?
Cancer cells have specific antigens called ‘tumour markers’ on their membranes
Monoclonal antibodies are specific to one type of antigen so can be targeted to ‘tumour markers’ without damaging other cells
70
Describe how monoclonal antibodies can be used to diagnose cancer
They are tagged to a radioactive substance
They are injected into the blood stream
They bind to
71
Why are cancer treatments that use monoclonal antibodies favoured over traditional treatments?
Radiotherapy and chemotherapy target rapidly dividing cells
Healthy cells are damaged as a consequence, producing unpleasant side effects
Monoclonal antibodies only target cancer cells, reducing damage to normal cells
72
How can monoclonal antibodies be used to locate blood clots?
They are tagged to a radioactive substance
They target and bind to specific proteins in blood clots
The radiation is detected, enabling the location to be identified
73
Give some examples of non-communicable diseases
Cancer
Diabetes
Cardiovascular diseases
Chronic respiratory diseases
74
What is a risk factor?
A variable associated with a greater chance of developing a disease or infection
75
Outline the factors that can affect the risk of developing a non-communicable disease
Lifestyle
Environmental
Genetics
76
Explain the statement “correlation does not mean causation”
Correlation. Between a risk factor and a disease does not mean the risk factor caused the disease
77
Describe how exercise affects the risk of some non-communicable diseases
Regular exercise decreases fat stores, reducing obesity
| It decreases heart rate, recovery time and blood pressure
78
Describe how diets affects the Rick of some non-communicable diseases
A high fat diet raises blood cholesterol levels, increasing the deposition of fatty deposits in the arteries
Obesity and the consumption of large amounts of simple sugars increases the risk of type 2 diabetes
Malnourishment increases the Rick of deficiency diseases
79
Give an example of a deficiency disease
Scurvy
| Anaemia
80
What is the body mass index?
A value based on height and mass used to categorise an individual as underweight, Normal, overweight and obese
81
How is BMI calculated?
Mass/height^2
82
Why isn’t BMI always an accurate measure of obesity?
Fat and muscle tissue cannot be distinguished so athletes may be incorrectly categorised as obese
83
How is waist to hip ratio calculated?
Waist circumference/hip circumference
84
Describe how alcohol affects the risk of some non-communicable diseases
It raises blood pressure
The toxic products in the alcohol can cause mutations to DNA increasing the risk of cancer
Alcohol broken down into toxic products in the liver which build up and cause scarring of liver tissue
85
Describe how smoking affects the Rick of some non-communicable diseases
Nicotine raises heart rate
Carbon monoxide lowers the ability of red blood cells to carry oxygen
Carcinogens in tar can cause mutations to DNA, increasing the risk of cancer
Increases the Rick of lung disease
86
How do environmental factors affect the risk of some non-communicable diseases?
Long term exposure to pollution damages the airways, Increasing the risk of lung diseases and cancer
Exposure to UV radiation damages DNA, increasing the risk of DNA mutations and skin cancer
87
How do genetics affect the risk of some non-communicable diseases?
Faulty genes can be inherited which increase the Rick of conditions such as breast cancer
88
How do diseases interact with each other?
Some may cause other infections to develop
| Some reduce the risk of contracting other infections
89
Describe the effects of non-communicable disease on a local level
An increased incidence of non-communicable disease puts a strain on local hospitals with limited resources
90
Describe the effects of non-communicable disease Ona national level
Increased pressure on NHS to provide treatment to a larger number of patients
91
Describe the effects of non-communicable disease on a global level
High prevalence of malnutrition in LEDCs slows the development of such countries which in turn impacts global development
92
What is cardiovascular disease?
Group of diseases affecting the heart or blood vessels
Build of of fatty deposits on the walls of the arteries forms at hero as which reduce blood flow to muscle tissue
Blood clots may form, blocking the arteries and stopping blood flow completely. This can lead to a heart attack or stroke
93
How can CVD lead to a heart attack?
Obstruction of a coronary artery due to an atheroma or blood clot
Results in loss of blood supply to an area of heart muscle
This causes death of the cells and leads to a heart attack
94
How can CVD be treated?
Improving diet and lifestyle
Medication
Surgery
95
What changes to diet and lifestyle can be made to reduce the risk of CVD?
```
Regular exercise
Reduce intake of saturated fat
Maintenance of a healthy weight
Diet low in salt
Reduce stress
Stop smoking and drinking alcohol
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96
How effecting are changes to lifestyle and diet in treating CVD?
Although they are not themselves effective, they can enhance the efficiency of other methods of treatment
97
Which three medicines are used to treat CVD?
Statins
Anticoagulants
Antihypertensives
98
Outline the benefits vs the risks of using statins to treat CVD
Stating lower the level of sholesterol in the blood
| However, they can cause liver damage, kidney failure or problems with memory
99
Outline the benefits vs the risks of using anticoagulants to treat CVD
They reduce blood clotting, lowering the risk of heart attack or stroke
They can cause excessive bleeding
100
Outline the benefits vs the risks of using antihypertensives to treat CVD
They lower blood pressure, reducing damage to artery walls and the build up of atheromas
They can have unpleasant side effects such as headaches, dizziness or fainting
101
What are stents?
Small, hollow tubes inserted into the lumen of arteries to keep them open
Require surgery to insert
102
What are the problems with the use of stents to treat CVD?
They cause the growth of scar tissue in the arteries over time, further narrowing the lumen
Blood clots may stick to stents
103
What is a coronary bypass?
Using a blood vessel from another region of the body to divert blood around a blockage in the coronary artery
104
What does a heart transplant involve?
Replacing a damaged heart with a donated heart
| Immunosuppressant drugs taken to prevent organ rejection
105
Describe the benefits of heart surgery
Life saving
| Can provide a permanent solution to a disease
106
Describe the risks of heart surgery
```
Involves many risks
Difficult to find a suitable donor
Risk or rejection
Immunosuppressant drugs must be taken for life
Long recovery time
Expensive
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