respiratory diseases. Flashcards
1
Q
Definition of pollutant? (3)
A
- Substance released into environment which can harm organisms or environment itself.
- They exert short-term effects -> irritation to tissues, allergic reactions.
- Extended exposure -> long-term effects -> chronic disease.
e.g., smoking -> increased risk of lung cancer + respiratory diseases.
2
Q
Examples of pollutants? (3)
A
- Tobacco smoke containing chemical pollutants (CO, tar, nicotine).
- Asbestos fibres -> lung cancer.
- Fungal spores -> Aspergillus mould -> aspergillosis in people with weak immune system.
3
Q
Acute - classification of disease? (3)
A
- Rapid onset.
- short duration - short term.
- relatively quick recovery.
e.g., acute bronchitis - caused by bacterial or viral infections, asthma ATTACK (asthma attack and bronchial spasm is acute).
4
Q
Chronic - classification of disease?
A
- slow onset.
- long duration.
- slow recovery (may be incurable).
- symptoms worsen over time.
e.g., chronic bronchitis -> long-term smoking, ASTHMA (inflammation is long term).
5
Q
Short-term effects of pollutants on the respiratory system? (4)
A
- Irritation of nose and throat.
- upper respiratory infections -> bronchitis and pneumonia.
- allergic reactions.
- aggravate the medical condition - asthma or emphysema.
6
Q
Long-term effects of pollutants on the respiratory system?
A
- chronic respiratory disease -> chronic bronchitis or emphysema, lung cancer.
- causing chronic obstructive pulmonary diseases - COPD.
7
Q
Causes of lung cancer? (4)
A
- specific DNA mutations.
- carcinogens -> tabacco smoke.
- tumour suppressor gene - benzopyrene activates p53.
- mutations to epithelial cells lining lungs -> formation of cancerous tumours.
8
Q
Stages of lung cancer development? (6)
A
- carcinogen or mutagen.
- carcinogen causes proto-oncogens to form oncogenes.
- uncontrolled mitosis.
- tumour forms.
- tumour may spread by metastasis.
- tumour may be maligant or benign.
9
Q
Symptoms of lung cancer? (9)
A
- usually no symptoms or signs in early stage.
- tumour may grow large enough -> blocking the airways.
- breathlessness.
- wheezing.
- persistant cough.
- blood-stained sputum.
- loss of appetite.
- fatigue.
- unexplained weight loss.
10
Q
Explanations of symptoms of lung cancer? (5)
A
- Mutation occurs -> changes proto-oncogens into oncogenes.
- cells divide by uncontrolled mitosis.
- cells change in their response to growth factors and cell signals.
- no programmed cell death occurs -> no apoptosis.
- cells do not differentiate and do not become specialised.
11
Q
Treatments for lung cancer?
A
- surgery.
- chemotherapy.
- radiotherapy.
12
Q
Asthma? (4)
A
- caused by inflammation + narrowing of bronchi.
- triggered by: fur, exercise, cold air, tobacco smoke.
- chronic condition.
- severe onset = acute asthma exacerbation = asthma attack.
13
Q
causes of asthma? (5)
A
- not fully known.
- genetic and environmental factors involved.
- increased risk of asthma if both parents have disease.
- many gene variants may also change disease.
- Increased risk linked to:
- smoking cigarettes.
- inhalation of other air pollutants.
- high ozone levels.
- inhalation of allergens - dust mite faeces, mould spores.
- specific allergies.
14
Q
Symptoms of asthma? (4)
A
- coughing.
- wheezing.
- difficulty breathing.
- chest tightness.
15
Q
Explanations of symptoms of asthma? (8)
A
- Cells lining bronchioles release histamines.
- Histamines make epithelial cells become inflammed and swollen.
- Histamines stimulate goblet cells.
- Mucus production increases in bronchi and bronchioles.
- Contraction of smooth muscle in bronchi + bronchioles walls.
- inflammation occurs -> swelling in walls.
- lumen of bronchi + bronchioles reduces.
- air flow restricted.
16
Q
Treatment for asthma?
A
- Incurable.
- Treatment manages the condition.
- Can be fast-acting.
- Can be long-acting.
- Inhalers deliver medication.
17
Q
Beta-agonist inhalers? (9)
A
- Relievers.
- Provides immediate relief.
- Some chemicals are similar to adrenaline.
- Chemicals attach to csm of smooth muscle cells in bronchioles.
- Relaxes the smooth muscle.
- Widens the lumen of bronchi.
- Acts as a bronchi-dilators.
- used prior to exercise or during asthma attack.
- some can be used in conjunction with steroids to provide long-term control.
18
Q
steriod inhalers? (6)
A
- preventers.
- corticosteroids used for long-term control.
- taken daily.
- reduces the sensitivty of the lining of airways.
- decreases probability + severity of attack.
- reduces inflammation of bronchi.
19
Q
Cause of chronic bronchitis? (1)
A
- tar deposits in the airways.
20
Q
Symptoms of chronic bronchitis?
A
- Shortness of breath.
- wheezing.
- fatigue.
- blood-stained sputum.
- persistant cough.
21
Q
Explanations of symptoms of chronic bronchitis? (8)
A
- hypertrophy of goblet cells (increase in size).
- Stimulates production of mucus from goblet cells.
- excess mucus paralyses cilia.
- cilia becomes unable to waft mucus up the throat.
- mucus accumulates in the airways with pathogens -> infections.
- excess mucus also reduces lumen of bronchi + bronchioles.
- mucus accumulates in alveoli -> increases diffusion distance for O2 and CO2.
- Inflammation occurs.
22
Q
Treatments for chronic bronchitis? (2)
A
- incurable.
- medication can be taken to reduce symptoms -> steroids + bronchodilators.
23
Q
causes of emphysema? (2)
A
- presence of bacterial filled mucus in alveoli.
- ventilation is impaired due to the destruction of elastic lung tissue.
24
Q
symptoms of emphysema? (9)
A
- chronic bronchitis + emphysema occur simultaneously.
- Together known as chronic obstructive pulmonary diseases - COPD.
- Shortness of breath.
- shallower breathing.
- difficulty in exhalation -> requires effort - has to become an active process due to lack of passive elastic coil.
- development of barrel chest - due to continual use of internal intercostal muscles.
- the partial pressure of oxygen in the blood is decreased.
Changes to lung structure: - Alveoli -> fewer alveoli -> ruptured alveoli, larger air spaces, smaller SA.
- Bronchioles -> no cilia in bronchioles, build-up of scar tissue, walls less folded, reduced smooth muscle, connective tissue, and elastin.
25
explanation of symptoms of emphysema? (10)
1. large no. of phagocytic WBC attracted to site of infection in alveoli.
2. phagocytes release elastase.
3. elastase digests tissue to enable phagocytes to reach infections.
4. elastase hydrolyses peptide bonds in elastin (protein) in alveoli walls.
5. inhibitor alpha-1 anti-trypsin (A1 AT) which prevents damage in healty person is deactivated in smokers.
6. alveoli becomes enlarged.
7. alveoli burst + becomes damaged.
8. reducing SA for gas exchange.
9. elastin becomes permenantly stretched - prevents elastic recoil.
10. so it becomes harder to remove stale air from lungs.
26
treatments for emphysema? (3)
Incurable.
1. emphysema and chronic bronchitis are treated together as COPD.
2. medication can be taken to reduce symptoms -> steroids + bronchodilators.
27
Discovering potential drugs. (3)
1. many new drugs are based on traditional folk medicine from plant products.
2. 50% of prescription drugs are derived from chemicals in plants or synthetic forms of plant products.
3. Chemicals from plants -> physiological effects on body that alleviate symptoms of disease.
28
Theophylline? (3)
1. Plant source: cocoa beans, tea leaves.
2. Physiological effect/propery: muscle relaxant - relaxes smooth muscles in bronchi walls, anti-inflammatory.
3. Treatment/use: COPD, asthma.
29
Topotecan? (3)
1. Plant source: Camptotheca acuminata
2. Physiological effect/propery: anti-cancer properties, anti-microbial properties.
3. Treatment/use: lung cancer, bacterial infections.
30
Xylopic acid? (3)
1. Plant source: Xylopia aethiopica.
2. Physiological effect/propery: anti-bacterial properties.
3. Treatment/use: bacterial infections.
31
Quinine? (3)
1. Plant source: Cinchona sp
2. Physiological effect/propery: reduces fever, painkiller, and anti-inflammatory.
3. Treatment/use: anti-malarial.
32
Aspirin? (3)
1. Plant source: Salix alba (willow)
2. Physiological effect/propery: anti-inflammatory, painkiller.
3. Treatment/use: painkiller, and anti-thrombic.
33
Paclitaxel? (3)
1. Plant source: Taxus brevifolia (yew tree)
2. Physiological effect/propery: inhibits mitosis.
3. Treatment/use: anti-cancer.
34
Why might it be difficult to discover new potential drugs now?
1. Thousands of species are under threat of extinction due to deforestation + climate change as plants may be extinct before the chemicals are discovered.
35
What is a clinical trial? (1)
1. Medicinal drugs being tested before they are liscened + avaliable for patient use.
36
What is a preclinical trial? (5)
1. testing done in a lab using
- cells
- tissues
- 2 different types of live mammals.
2. can take 5.5 years.
3. if drug is considered safe + effective, it will then enter clinical trials.
4. only 0.1% of new drugs reach clinical trials.
5. can cost £533 million.
37
Prior to clinical trial? (3)
1. detailed plan + justification submitted to research committee (Medical + Healthcare Products Regulatory Agency)
2. researchers must prepare information leaflets for patients: needs to be in plain language + outline the following:
- research questions being asked.
- who can participate in the trial + who can't.
- what treatment is being used.
- possible risks to patients.
- possible benefits to patients.
- who is funding the trial.
- who is conducting the trial.
3. research comittee checks leafleft for accuracy + clarity -> then gives approval for clinical trial.
38
Clinical trial?
1. 4 phases within clinical trial.
2. new drugs extensively tested for:
- toxicity: whether or not they might cause harm.
- efficacy: how well they work.
- dose: how much needs to be taken for the best results.
3. Placebos: tablets + capsules that look identical to the new drug but contain no active ingredient -> dummy tablet with no actual drug in them.
4. Must have the same taste, smell, and look identical to actual drug (but no effect on patient in any way).
5. Placebos are used to ensure valid + reliable data is collected with no bias.
Patients are randomly allocated to groups.
> single blind trial = the patient doesnt know whether they are being given a placebo or the real drug but the doctor does.
> double blind trial = some patients get placebo, some patients get real drug, but neither the patient or the doctor knows what the patient takes until the trial is complete.
> Triple blind = some patients are given a placebo and some patients the real drug, neither the patient or the doctor know what the patient takes until the trial and data processing is complete.
6. Double blind allowss for placebo effect = when the patient expects to feel better as they are taking the medication, and also prevents subconscious bias from doctors when reporting how effective the drug has been.
7. Results are published only after scrutiny by peer review.
39
what is peer review? (1)
1. when other scientists check the work of the original scientist to make sure the testing has been rigorous enough. This helps prevent false claims.
40
Phase 1 of clinical trials? (6)
SAFETY!!!
1. Involves 10-20 healthy people.
2. Takes 7 years.
3. costs £710 million.
4. patients given low doses -> doses increase until the upper limit of a safe dose is established.
5. clinical trials use health volunteers and patients -> initially new drug is given to healthy individuals (to check for side effects).
6. If the drug is found to be safe, further clinical trials are carried out on individuals with the appropriate disease/disorder to find the optimum dose for the drug -> the dose with the best efficacy with minimal side effects.
41
phase 2 of clinical trials? (7)
EFFICACY!!!
1. involves 200 people.
2. takes 8.5 years.
3. costs £916 million.
4. phase assesses effectiveness of drug.
5. determines if it is efficient enough to enter phase 3.
6. often uses a placebo.
7. 50% healthy volunteers randomly given actual drug while 50% given placebo.
42
phase 3 of clinical trials? (11)
CONFIRMATION OF RESULTS!!!
1. new drug compared to current already licensed treatment.
2. involves 1000s of participants.
3. takes 11 years.
4. costs £1100 million.
5. participants have the disease -> placebo not used -> unethical.
6. new drug might be slightly more effective than current already licensed drug.
7. large sample size needed to enable sufficient data to be collected for statistical analysis.
8. data analysis determine if there is a significant difference in the benefits.
9. trials are randomised -> ppts either receive new drug or established drug.
10. ppts should be of the same age, ethnic background (affects genetics), gender, lifestyle (smoker, physical activity level).
11. Licensing of drug - subject to all standard and legal requirements.
43
phase 4 of clinical trials? (5)
1. takes 12.5 years.
2. costs £1150 million.
3. occurs post licensing.
4. doctors can prescribe the drug.
5. phase enables long-term benefits to be assessed + possible side effects monitored.
44
Role of NICE - National Institute for Health + Care Excellence?
1. Independent UK organisation that assesses clinical + cost effectiveness of health technologies.
2. For new drugs, it is diagnostic agents, procedures, and devices used in health care.
3. Aim = enable all NHS patients to have access to most clinically + cost effective treatment avalible.
4. drugs can only be prescribed on NHS using NICE guidelines.
5. new drugs can be effective but costly.
6. NICE evaluates whether effectiveness of drugs is sufficient to justify funding it's use.
7. Organisation also issues guidance on appropriate treatment + procedures for specific diseases or conditions based on most research findings.
