XABY02 RESP, CARDIO,CANCER, GENETICS Flashcards
1
Q
What kind of disease is Pulmonary Tuberculosis?
A
Respiratory disease
2
Q
How is Pulmonary tuberculosis spread?
A
Spread through air by droplets released when infected person coughs/sneezes
3
Q
Is pulmonary tuberculosis very contagious?
A
no, normally takes close contact with infected person over period of time to transmit bacteria
4
Q
What happens after inhalation of Pulmonary Tuberculosis bacteria? (3)
A
- bacteria grow and replicate within upper regions of lungs where there is a rich oxygen supply
- Phagocytic white blood cells ingest bacteria
- Bacteria encased in structures known as tubercles (nodules)
5
Q
What happens in healthy people when Pulmonary Tuberculosis bacteria is inhaled?
A
- in healthy people, immune system prevents TB in tubercles from developing further so bacteria are inactive and do not replicate
6
Q
What happens in people with immunosuppression when Pulmonary Tuberculosis bacteria is inhaled?
A
- Bacteria may become activated and begin to replicate
- they may damage/destroy alveolar wall and blood capillaries
- results in fibrosis and reduction in gas exchange
- Bateria may also spread to other organs and cause damage
7
Q
What are the 5 symptoms of TB?
A
- persistent cough (coughing up blood)
- breathing difficulties
- fatigue and loss of appetite that (leads to weight loss)
- fever and night sweats
- chest pain
8
Q
Why have TB cases increased increased throughout the world?
A
TB bacteria have mutated to produce new antibiotic resistant strains
9
Q
What is the main preventative measure for TB?
A
BCG vaccination made from weakened strain of TB
10
Q
How effective is the BCG vaccine?
A
- 70-80% effective against most severe forms of TB such as TB meningitis in children
- but is less effective in preventing respiratory diseases (the more common form of TB in adults)
11
Q
What are other preventative measures of TB spread?
A
- better education about TB, particularly the need to complete all medication courses
- isolate TB sufferers
- improved health facilities and treatments
- better nutrition to ensure immune systems not weakened
12
Q
How is TB treated?
A
- uses antibiotics to kill bacteria
- RIFAMPICIN
- ISONIAZID
13
Q
How long are the courses of antibiotics needed to completely eliminate TB from the body?
A
6-12 months
14
Q
What is ‘Directly Observed Treatment, Short-Courses’ (DOTS)?
A
involves patient being monitored to ensure they complete the course of antibiotics to reduce possibility of emergence of antibiotic-resistant strains
15
Q
When may surgical treatment of TB be used?
A
if medications are ineffective
16
Q
What does surgical treatment of TB involve?
A
one or more ribs are removed and a diseased lung (in whole or in part) is removed)
17
Q
What is asthma?
A
A disease affecting the bronchioles
18
Q
What happens when a person with asthma comes into contact with something that irritates the bronchioles? (5)
A
- muscle around walls of bronchioles contract
- lining of bronchioles become inflamed and swell
- over-production of sticky mucus (by bronchiole lining)
- reduces flow of air down bronchioles therefore lower volume of oxygen reaches alveoli
- reduces concentration gradient and therefore rate of gas exchange
19
Q
What is an inhaler?
A
contains drugs that cause walls of bronchioles to relax and widen so greater volume of air (oxygen) reaches the lungs
20
Q
Why does asthma differ from other lung diseases? (2)
A
- surface area of alveoli and elasticity of lungs not affected
- fibrosis due to scarring does not occur
21
Q
What are 4 symptoms of asthma?
A
- shortness of breath (constriction of bronchioles)
- wheezing noise (air passing through very constricted bronchioles)
- tightening of chest (due to improper ventilation of lungs)
- coughing (reflex to clear narrow bronchioles of any obstruction)
22
Q
What is Pulmonary fibrosis?
A
arises from scarring of lung tissue as fibrous connective tissue forms due to disease (e.g. TB) or damage
23
Q
What two things does scarring of the lungs cause?
A
- lining of alveoli to thicken reducing efficiency of gaseous exchange due to longer diffusion distance
- lungs to become less elastic - greatly affects ability to breathe out as relies on elastic recoil of lung tissue
24
Q
Why does shortness of breath occur in sufferers of PF?
A
- thickened epithelial lining of alveoli increases diffusion distance, diffusion of oxygen very slow
- loss of elasticity makes ventilation (particularly expiration) difficult, hard to maintain diffusion gradient
- reduced oxygen in blood results in reduced rate of respiration, reduced production of ATP therefore less ATP for muscle contraction
25
Why do sufferers of PF have chronic, dry coughs?
- because fibrous tissue creates obstruction in airways of lungs
- body's reflex is to remove obstruction by coughing
- since fibrous tissue immovable, nothing expelled so cough is dry
26
Why do sufferers of PF have pain and discomfort in the chest?
consequence of pressure and damage from mass of fibrous tissue in lungs and further damage due to coughing
27
Why do sufferers of PF have weakness and fatigue?
result from reduced intake of oxygen into blood - rate of respiration decreases so less energy released - leads to fatigue
28
What is emphysema?
disease caused by progressive destruction of walls of alveoli leading to development of larger air spaces
29
What is emphysema caused by?
mainly by smoking, although air pollution may also be a factor
30
How does emphysema lead patient to become breathless even with minimum exercise?
- development of larger air spaces reduces surface area of alveoli
- alveolar walls become damaged and thicken
- gas exchange far less efficient due to reduced surface area and increased diffusion pathway
- loss in elasticity of lung tissue (due to loss of elastin) so lungs are unable to force out all air during expiration - reduces concentration gradient and therefore rate of diffusion
- as a result lungs ability to supply blood with oxygen progressively decreased
- lack of oxygen to muscles of body reduces respiration and energy available
31
Why do emphysema patients experience shortness of breath?
- difficulty in exhaling air due to loss of elasticity in lungs - if lungs cannot be fully emptied it is difficult to inhale fresh air so patient feels breathless
- smaller alveolar surface area leads to reduced levels of oxygen in blood so patient tries to increase oxygen supply by breathing more rapidly
- barrel-shaped chest - because of breaking down of the alveoli, air becomes trapped in the enlarged alveolar spaces and lungs become over-inflated
32
Why do emphysema patients experience a chronic cough?
consequence of lung damage and body’s effort to remove damaged tissue and mucus that cannot be removed because cilia on bronchioles has been destroyed
33
Why do emphysema patients experience a bluish skin colouration?
due to low levels of oxygen in blood as a result of poor gas diffusion in the lungs
34
How is a diagnosis of emphysema made?
- lung function tests
- chest X ray
- measurements of blood oxygen and CO2
- sputum examination
35
What will a lung X-ray show for someone with emphysema?
abnormally translucent lungs with few normal blood vessel markings
36
Can emphysema be cured?
no, because damaged lung tissue cannot be replaced
37
What are the forms of treatment for emphysema?
1. stop smoking to prevent further damage
2. antibiotic drugs to help control infection
3. non-invasive positive-pressure ventilation = wearing nasal mask at night, supplied with air slightly higher than atmospheric pressure
4. bronchodilators taken by inhaler
5. steroids to reduce inflammatory swelling
6. oxygen therapy
7. alpha-1-antitrypsin enzyme replacement in those deficient of it
8. exercise to increase physical ability
9. surgery to remove worst affected part of lungs
38
What does cardiovascular disease refer to?
disease of heart and circulatory system
39
What does coronary heart disease affect?
coronary arteries (which supply heart muscle with glucose and oxygen)
40
What are atheromas?
fatty deposits, particularly cholesterol and LDL's under wall of an artery under endothelial lining
41
What do atheromas do in CHD?
- reduce blood flow along coronary arteries
| - increase risk of myocardial infarction
42
What is the most common form of cardiovascular disease?
atherosclerosis
43
What is the process leading to atherosclerosis?
- deposit of yellow fatty streaks high in cholesterol in inner coats of arteries
- deposits form beneath endothelium of blood vessel
44
what are fatty deposits known as?
atheromatous plaques
45
what happens to the process of atherosclerosis to become arteriosclerosis?
- fibres deposited in cholesterol
| - these calcify and become hard
46
What happens to the blood vessel as plaques increase in size?
- plaque protrudes into lumen of artery and begins to block it
- narrowed artery = blood flow reduced and blood pressure increased
47
How can atheromas lead to myocardial infarction?
- reduced oxygen supply to heart muscle due to reduced blood flow
- heart muscle deprived of oxygen, cannot respire and dies
- some heart attacks result in heart stopping completely
48
What is myocardial infarction often preceded by?
Angina - chest pain resulting from inadequate blood supply to cardiac muscle rather than complete blockage
49
What are 4 other diseases linked to atheromas?
1. thrombosis
2. aneurysm
3. peripheral vascular disease
4. cerebrovascular accident
50
What is thrombosis?
- formation of a blood clot
51
How does thrombosis occur?
- atheroma breaks through endothelium of blood vessel
- forms a rough surface interrupting smooth flow of blood
- results in formation of blood clot (thrombus)
52
What is an embolus?
- a thrombus carried from place of origin and blocking another artery
53
What is an aneurysm?
- atheromas leading to formation of blood clot also weaken artery walls
- weakened points swell to form balloon-like blood filled structure called ANEURYSM
- aneurysms often burst leading to haemorrhage and therefore loss of blood to body part
54
What must be done when there is danger of aneurysm bursting?
- in surgery, section of artery replaced by synthetic tube
55
What is peripheral vascular disease?
- narrowing of the arteries, particularly in lower extremities
56
What are the dangers of Peripheral vascular disease?
- increased risk of thrombosis obstructing arteries
| - circulatory problems with inadequate oxygen supplied to legs, feet etc. (increases risk of infection)
57
What is cerebrovascular accident?
- obstruction of cerebral artery which supplies blood to specific areas of brain
58
how may an atheroma cause cerebrovascular accident?
- atheroma may cause blockage increasing risk that blood clot complete blocks artery
59
where do clots often arise from?
carotid arteries in neck and then travel to the brain, blocking arteries supplying the cerebellum
60
what is the most common form of stroke?
ischaemic stroke
61
what does bleeding from arteries in the brain cause?
- directly damages brains tissue
| - loss of blood supply
62
what do symptoms experienced depend on?
- area of brain deprived of oxygen
63
what are symptoms of cerebrovascular accident?
slurred speech, confusion, difficulty in walking, arm and leg weakness and numbness along one side
64
why are males more at risk of developing cardiovascular disease?
not as much lipid used up in synthesis of hormones such as oestrogen and progesterone
65
why does CVD risk increase with age?
fat is deposited in walls of arteries throughout life
66
why does smoking increase risk of CVD?
- chemicals in smoke diffuse into blood of alveoli
- affect properties of endothelial cells of arteries
- increases uptake of fat
- nicotine increases heart rate and blood pressure
- nicotine also linked to higher blood cholesterol levels
67
why does stress increase risk of CVD?
- increases blood pressure
| - affects hormone levels which may lead to fat deposition in arteries
68
how does diet affect the risk of CVD?
- cholesterol essential component of plasma membranes, transported in blood plasma as tiny spheres of lipoprotein
- HDL remove cholesterol from tissues and transport it to liver for excretion (decreases risk)
- LDL transport cholesterol from liver to tissues, including artery walls (increases risk)
69
what increases blood pressure?
- genetic factors
- excessive levels of stress
- excessive salt in diet
- lack of exercise
- smoking
70
how does genetic predisposition affect risk of CVD?
- most blood cholesterol produced by liver and overproduction appears to be result of genetic factors
71
how does exercise affect risk of CVD?
- decreases it
- decreases levels of blood lipid as used up in respiration
- increase in rate of blood flow during exercise reduces build up of fat deposit and clot formation
72
How does diabetes affect risk of CVD?
- metabolism of both glucose and lipid affected by lack of insulin
- insulin injections may lead to imbalance of lipid in blood and consequently risk of atheroma developing
73
what is a risk factor?
anything that increases chance of getting a disease (e.g. diet, smoking, sex, occupation)
74
what are risk factors associated with CVD?
- smoking
- high blood pressure
- high blood cholesterol levels
- prolonged stress
- lack of exercise
75
what are risk factors of lung disease?
- smoking
- air pollution (sulphur dioxide)
- infections
- genetic makeup
- occupation
76
what are risk factors of cancer?
- smoking
- diet
- obesity
- sunlight
77
what is a correlation?
- when change in one or two variables reflected by a change in other variable
- not actual evidence
78
what is causation?
- factor that is directly a cause of disease
| - only established by scientist producing compelling evidence to show factor is a cause
79
what is a relative risk?
- risk measure by comparing likelihood of harm occurring in those exposed to hazard with those not exposed
80
what is cancer?
- uncontrolled growth and rapid division of cells
81
what is cancer a result of?
- damage to genes that regulate mitosis and the cell cycle
82
what is metastasis?
- cancer cells break away and move to other areas of body
- particularly in blood/lymphatic system
- causes secondary cancers/metastases
83
what are malignant tumours?
- fast growing
- invade surrounding tissue
- have the potential to spread round the body via lymphatic channels/blood vessels as not enclosed
84
what are benign tumours?
- slow growing
- non invasive
- do not spread as enclosed in fibrous tissue
85
CELLS: malignant vs benign
undifferentiated (non-specialised) vs differentiated
86
NUCLEUS: malignant vs benign
larger and darker vs relatively normal appearance
87
what are the effects of tumours?
- may damage organs affecting their function
- cause blockages in blood vessels, lymphatic vessels and ducts
- exert pressure on other organs causing problems (pressure on nerves/brain)
- cause new capillary networks to form diverting blood away from tissues (angiogenesis)
88
what do proto-oncogenes do?
stimulate cell division
89
what do tumour suppressor genes do?
slow cell division
90
what does a mutated proto-oncogene do?
stimulates cell division too quickly (called an oncogene)
91
what does a mutated tumour suppressor gene do?
inactivates it, allowing rate of cell division to increase
92
what can also cause cancer apart from gene mutations?
- viruses (cervical cancer - HPV)
| - increased concentrations of hormones (breast cancer - oestrogen)
93
(CANCER RISK) name two examples of chemical carcinogens
1. asbestos
| 2. cigarette tar
94
(CANCER RISK) name two examples of ionising radiation
1. high energy particles (alpha, beta)
| 2. short wave electromagnetic radiation (UV light, X rays, gamma rays)
95
How can diet increase risk of cancer?
- lots of processed meat, cooking meat until it chars (polycyclic aromatic hydrocarbons)
- increased fat (free radicals)
96
How can diet decrease risk of cancer?
- fruit and veg (antioxidants that protect against free radical damage)
- fibre (increases transit time)
97
what are 6 treatments for cancer?
1. surgery
2. radiotherapy
3. chemotherapy
4. immunotherapy
5. monoclonal antibodies
6. hormonal therapy
98
how does radiotherapy work?
- ionising radiation induces DNA damage triggering cell death
- radiation doses divided to allow for recovery of normal tissue and reduce side effects
99
how does chemotherapy work?
- damages DNA of rapidly dividing cells triggering cell death
- damaging spindle apparatus, preventing cell division
- inhibiting DNA synthesis (inhibiting DNA helicase and DNA polymerase)
100
how does immunotherapy work?
interleukin 2 induces small remission rate in some cancers
101
how do monoclonal antibodies work?
- antibodies recognise cancer cells and mark them for destruction by immune system
- radioactive atoms and chemo drugs can be attached antibodies
102
how does hormonal therapy work?
some tumours (breast/prostate) respond well to inhibition of certain hormones (Tamoxifen reduces oestrogen activity)
