Topic 5 Health And Disease Flashcards
1
Q
Define health.
A
A state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity - WHO definition.
2
Q
Define disease.
A
A condition where part of an organism doesn’t function properly.
3
Q
What are the two types of disease?
A
- Communicable
- Non-communicable
4
Q
What is a communicable disease?
A
Diseases that are spread between individuals.
5
Q
Define pathogen.
A
Organisms such as viruses, bacteria, fungi, and protist that cause a communicable disease.
6
Q
What is a non-communicable disease?
A
Disease that can’t be transmitted between individuals and include stuff like cancer and heart disease.
7
Q
What is a symptom?
A
A change experienced by an organism indicating disease presence.
8
Q
Why does illness increase susceptibility to other diseases?
A
Weakens the immune system.
9
Q
Describe cholera.
A
- Caused by bacteria, Vibrio cholerae
- Spread via contaminated water
- Symptoms: diarrhoea
10
Q
How do you reduce cholera incidence?
A
Making sure people have access to clean water supplies.
11
Q
Describe tuberculosis (TB).
A
- Caused by bacteria, Mycobacterium tuberculosis
- Air transmitted - coughing
- Symptoms: lung damage, cough
12
Q
How do you reduce TB transmission?
A
- Improved hygiene
- Avoid crowded areas
- Ventilation
- Sleep alone
13
Q
Describe Chalara ash dieback.
A
- Fungal disease infects ash trees
- Spread by wind and when infected ash trees move area
- Causes leaf loss and bark lesions (wounds)
14
Q
How do you reduce Chalara spread?
A
- Control ash tree movement
- Kill infected plants
- Replant different species
15
Q
Describe malaria.
A
- Caused by Plasmodium protist
- Mosquito vector passed to humans
- Symptoms: Damage to red blood cells and severe cases damage to liver
16
Q
How do you reduce malaria incidence?
A
- Mosquito nets
- Insect repellent
- Cover skin
17
Q
Describe stomach ulcers.
A
- Caused by Helicobacter pylori bacteria
- Transmitted orally, e.g., swallowing water or food
- Symptoms: stomach pain, nausea, and vomiting
18
Q
How do you reduce stomach ulcers transmission?
A
- Clean water
- Hygiene
- Sanitation
19
Q
Describe Ebola.
A
- Virus
- Spread via body fluids
- Symptoms: fever, bleeding (haemorrhagic)
20
Q
How do you reduce Ebola transmission?
A
- Hygiene
- Isolation
- Sterilisation
21
Q
How do viruses cause disease?
A
Enter host cells, replicate, and damage cells.
22
Q
How do viruses differ from bacteria/fungi?
A
They are considered not living and replicate only in host cells.
23
Q
Virus replication pathways?
A
- Lytic pathway
- Lysogenic pathway
24
Q
Describe the lytic pathway.
A
- Virus binds host and injects genetic material
- Replicates DNA using proteins and enzymes in the host
- Assembles viruses
- Host cells split open, releasing the new viruses
25
Describe the lysogenic pathway.
1) The virus puts its genes into the cell's DNA.
2) When the cell divides, the virus's genes copy too, but stay asleep.
3) A trigger (like a chemical) wakes the virus, making it leave the DNA and create new viruses in the lytic pathway
26
Describe HIV. Virus.
- Destroys white blood cells
- Leads to AIDS
- Spread via body fluids
27
Reduce HIV spread?
- Condoms
- Needle exchange
- Blood screening, e.g., after pregnancy
28
Describe Chlamydia. Bacteria.
- Bacterial STI
- Causes infertility
- Spread via sexual contact
29
Reduce Chlamydia spread?
- Condoms
- Screening
- Avoid sexual contact
30
Describe plant physical defences.
- Waxy cuticle, which also stops water collecting on the leaf, stopping the risk of infections through water
- Cellulose cell wall barrier after the waxy cuticle
31
What do plants produce to deter bacteria, fungal, and insects.
- For bacteria and fungal plants produced antiseptics which kill them
- For insects, they may produce chemical on their leaves to stop them from feeding on them.
32
Why are plant chemicals useful?
Used in medicines to treat human diseases or relieve symptoms.
33
What are the two examples of medicine made by plant chemical barriers?
1. Quinine comes from the bark of cinchona, which was the main treatment for malaria
2. Aspirin comes from bark and leaves of willow trees and is used to relieve pain and fever
34
Why are plant defences important?
- Maintain food chains
- Ensure food security
35
How do we detect plant diseases in the field?
- Observe symptoms with plant pathologists
- Analyze distribution of diseased plants
- Change environmental conditions and observe any changes
36
What are some examples of how diseases are detected in the field? (3)
1. Galls ( abnormal growth) may mean crown gall disease in many plants, including apples and others
2. Yellow leaves may be from nutrient deficiency
3. If disease plants in a field have patches, it may suggest it was spread through soil, if its more random, it suggests an airborne pathogen.
37
How do we detect plant diseases in the lab?
- Using monoclonal antibodies
- DNA analysis in plant tissue
38
What are the body’s physical defences? (4)
- Skin
- Blood clotting to stop microorganisms
- Hair + Mucus in your nose strap airborne pathogens
- Trachea and Bronchi (airways in the lungs) produce mucus, which traps pathogens.
39
What are the body’s chemical defences? (2)
- Lysozyme in tears kills bacteria on the surface if your eye
- Stomach produces hydrochloric acid, which kills pathogens
40
What is the immune system?
Defence for your body if a pathogen passes your barriers.
41
How does the immune system destroy pathogens?
When the B-lyphocytes come across a pathogen, they produce a protien called antibodies, which bind to the pathogen so it can be found by white blood cells and be destroyed. They then are produced rapidly and flow around your body to hunt more.
42
What are memory lymphocytes?
They stay in your body for a long period of time after you overcome the infection and remember the specific antigen. Making the person immune to the infection.
43
Compare primary and secondary immune response.
Secondary responses are faster as the immune system has memory lymphocytes, which remember the antigen so the body can respond quickly if a second infection takes place.
44
What is a vaccination?
Exposure to antigens to trigger the immune system to create antibodies and memory lymphocytes.
45
What are the components of vaccination?
Dead or inactive pathogens with antigens are used.
46
What are the benefits of vaccines?
- Herd immunity
- Prevent epidemics (rapid increase)
47
What are the drawbacks of vaccines?
- Doesn't always work
- Side effects
- Bad reactions, e.g., swelling, fever, seizures
48
What is an antibiotic?
Inhibits processes of bacteria, e.g., inhibits bacteria cell walls. Different antibiotics treat different bacteria, so it's important to use the right one.
49
Stages of drug development?
1. Scientists find or design new drugs that might treat a disease.
2. Preclinical Testing - The drug is tested in labs on cells and animals to check if it's safe and works.
3. Clinical Trials - The drug is tested on healthy volunteers and patients to check safety, dosage, and effectiveness.
4. If the drug passes all tests, it's approved and can be prescribed to patients.
50
What are placebos?
A substance that looks like the drug that is being tested but doesn't do anything.
51
What is a blind trial?
The patient doesn't know whether they have the drug or the placebo until the results have been gathered.
52
What is a double-blind trial?
The patient and the doctor don't know whether the patient has the drug or the placebo until the results have been gathered.
53
Why can't you use preclinical testing in the lab to test some drugs?
A drug for blood pressure must be treated on a whole animal as it is not possible to check the full effects on cells and tissues.
54
What are monoclonal antibodies?
Cloned antibodies specific to one antigen.
55
How can you produce monoclonal antibodies?
• Inject an antigen into a mouse.
• The mouse's immune system makes B-lymphocytes that produce antibodies.
• These B-lymphocytes are collected from the mouse.
• They are then fused with tumour cells to make hybridomas.
• The hybridomas divide and make lots of identical antibodies (monoclonal antibodies).
56
How did Alexander Fleming discover Penicillin?
He noticed mould growing on a bacteria-filled Petri dish.
The area around the mould had no bacteria bc it was killing them.
The mould was penicillin, the first antibiotic.
57
How does a pregnancy test stick detect HCG hormone in urine using monoclonal antibodies?
1. The test has antibodies with blue beads that bind to HCG.
2. The test strip also has fixed antibodies that can catch HCG.
3. If pregnant, HCG in urine sticks to the blue beads, then to the strip. Making a blue line.
4. If not pregnant, there's no HCG, so nothing sticks to the strip. No line appears.
58
What do monoclonal antibodies help us with?
1. Pregnancy tests
2. Find cancer cells
3. Treat drugs to cancer
4. Find blood clots
59
How can monoclonal antibodies help with cancer?
- Tumour markers are unique proteins on cancer cells, cell membranes
- Monoclonal antibodies can be made to bind to these markers.
- Used to diagnose and treat cancer
60
How do radioactive antibodies help find cancer?
1. Label antibodies with a radioactive element
2. Inject into blood via drip, they travel through the body
3. Bind to cancer cells targeting tumour markers
4. Scan with a special camera, so any bright spots mean cancer
5. Doctors see tumour location, size, and spread
61
How do antibody-based cancer drugs work?
1. Monoclonal antibodies carry drugs and are injected into the patient.
2. They target only cancer cells since they bind to tumour markers.
3. Drug kills cancer, spares healthy cells.
4. There are fewer side effects vs. drugs and radiotherapy.
62
How can monoclonal antibodies help detect blood clots?
1. Monoclonal antibodies bind to clotting proteins in blood.
2. Radioactive tag added to antibodies.
3. Injected into body, they stick to clots.
4. Special camera scan shows bright spots, which are clot locations.
5. Find a potentially harmful blood clot.
63
What is a risk factor?
Things that are linked to an increase in the likelihood that a person will develop a certain disease during their lifetime.
64
What are factors affecting non-communicable disease risk? (3)
- Lifestyle
- Environment
- Genetics
65
What is BMI?
Weight/height² to learn if someone is underweight, normal, overweight, or obese.
66
What is BMI's limitation?
Doesn’t distinguish muscle over fat.
67
Waist-to-hip ratio formula?
Waist circumference ÷ hip circumference
68
What are waist-to-hip ratio risks?
Above 1.0 for males and above 0.85 for females suggests you carry too much weight around your middle, putting you at a higher risk of obesity problems.
69
What is cardiovascular disease (CVD)?
Any disease associated with your heart and blood vessels.
70
What causes CVD? (4)
1. Cholesterol is needed for cells, but if there are too many fatty substances, deposits in arteries.
2. Artery becomes damage, causing high blood pressure, which weakens artery walls.
3. Fatty deposits narrow arteries and restrict blood flow.
4. Blood clots can block arteries completely, so no oxygen is delivered.
Heart attack = Blockage in heart artery. Stroke = Blockage in brain artery.
71
How do we treat CVD?
- Lifestyle changes
- Medication
- Surgery
72
How can we reduce CVD risk?
- Exercise
- Healthy diet of low saturated fats to lower cholesterol levels
- No smoking/alcohol
73
What are CVDs 3 medications?
- Statins
- Anticoagulants
- Antihypertensives
74
What are statins?
- Reduce cholesterol in the blood
- Slows down the rate of fatty deposits forming
- Reduces the risk of heart attacks and strokes
- Can cause side effects, eg, aching muscles
- Some can be serious, e.g., liver damage
75
What are anticoagulants?
- For E.g, Wafin are drugs that make blood clots less likely to form
- They can cause excessive bleeding if the person is hurt
76
What are antihypertensives?
- Reduce blood pressure
- Prevent damage to blood vessels
- Reduces the risk of fatty deposits forming
- Cause side effects eg headaches and fainting
77
What are stents?
Tubes that are inserted into arteries keep them open, making sure blood can pass to the heart muscles, lowering the risk of a heart attack.
78
What are stents' risks?
- Irritate the artery and scar tissue
- The patient has to also take drugs to stop blood clotting on the stent
79
What are coronary bypasses?
A healthy vessel of a blood vessel can be taken from somewhere less to be used to bypass the blocked section.
80
What is heart transplantation?
Replacing your heart for someone else's. The new heart may be rejected by the body, so drugs need to be taken.
81
What are heart surgery benefits?
Lifesaving, permanent solution.
82
What are heart surgery risks?
The drugs taken have side effects, making you more vulnerable to infections, bleeding, and clots.
83
What do non-specific barriers mean?
Physical and Chemical barriers that work against many types of pathogens.
84
What does radiotherapy involve?
Firing high-energy beans (like X-rays) straight at a tumour, which can kill tumours as well as other cells.
85
What are the risk factors of a non-communicable disease that a person can not avoid? (4)
- Age
- Gender
- Genetics
- Ethnicity
86
What are lifestyle factors associated with cardiovascular disease? (5)
1. Smoking
2. Unhealthy diet
3. No exercise
4. Consumption of alcohol
5. Obesity
87
How is smoking a risk factor?
1. Nicotine raises heart rate & blood pressure.
2. High BP damages arteries fatty deposits build up.
3. Narrowed arteries mean less blood flow and heart attack/stroke risk.
4. Blood clots form easier and can block arteries completely.
88
How is unhealthy diet a risk factor?
A diet with too many or too few nutrients can lead to malnutrition and diseases associated with it, e.g. scurvy, which is a vitamin C deficiency disease.
89
How is no exercise a risk factor?
No exercise with a diet high in fat and sugar leads to obesity.
90
How is the consumption of alcohol a risk factor?
Develops liver disease, e.g., cirrhosis (scarring of the liver). This is bc when enzymes break down alcohol in the liver, products released are toxic, and drinking over a long period of time may cause permanent liver damage.
91
How is obesity a risk factor?
It causes other non-communicable diseases, e.g., type 2 diabetes and cardiovascular disease.
92
How do non-communicable diseases have an economic effect in local areas?
- High occurrence of non-communicable diseases in an area could lead to more need of recourses, e.g., beds, staff, etc.
- Having more people in the hospital than at work causes an economic reduction.
- This can hold back the development of the country.
93
Describe the BMI table.
Below 18.5 = underweight
18.5-24.9 = normal
25-29.9 = overweight
30-40 = moderatley obese
Above 40 = severely obese
94
How is environment a risk factor?
- Contamination of air and water
- Radiation
- Climate change
95
How is genetics a risk factor?
Having alleles that contain negative genetics will cause you to inherit diseases, e.g., breast cancer.
96
How are interactions a risk factor?
Between individuals or species interactions can significantly increase the likelihood of developing diseases, e.g., HIV.
