Download Lung disorders

Lung disorders
Unit 4C section C.3
CSE
November 2006
Bronchitis
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Term for a wide variety of chest conditions
Acute bronchitis is infectious but more common in
smokers and their families, workers in environments
with irritant particles and people living in highly
polluted areas
Acute = comes on quickly and is short term
Chronic bronchitis – linked with environmental
factors eg smoking
Chronic = comes on gradually and lasts a long time
Chronic bronchitis
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Secretes too much mucus in airways causing a
persistent cough
Airways permanently irritated, vulnerable to infection
Cause narrowing of bronchioles and chronic
shortness of breath
Lungs can be permanently damaged
Life threatening disease, 300 000 in UK die each year
Diagnosis by lung measurements eg peak flow, vital
capacity
Chronic bronchitis
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Increases with age
 More common in men
 Twice as common in urban dwellers cf rural
 More common in unskilled people
 Genetic factors affect risk
 Exposure to dust increases chance
 Smokers – 15-20% develop it
Effects of chronic bronchitis
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Swelling of epithelial membranes of airways restricting
air passage and causing breathlessness
Excess mucus from goblet cells
Cilia damage
Dirty mucus collects in tubes, restrict air movement and
gas exchange
Cough – reflex action
Right ventricle fails – beats rapidly but not effectively –
blue tinge
Build up of scar tissue on bronchi and bronchioles due to
coughing – results in even thicker walls and less air flow
Infections eg pneumonia due to bacteria accumulation
Emphysema
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Kills 20 000 per year in UK from respiratory failure,
infections or heart failure as heart enlarged to pump
blood through arteries constricted due to lack of oxygen
Develops over time eg 20 years
Impossible to diagnose until lungs irreversibly damaged
Early stages – slight breathlessness
Breathe heavily and hunched to try to get more air in
Chest barrel shaped, noisy hyperventilation often
leading to pink colour
Late stages – can’t get out of bed
Causes of emphysema 1
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Healthy lungs contain large quantities of elastic
connective tissue made of protein elastin which
expands when breathe in and returns to normal
size when breathe out
 In emphysema, elastin has become permanently
stretched and lungs can’t force out all the air from
the alveoli
 Alveoli surface area reduced and can burst so little
gas exchange
 Due to high levels elastase, made in WBC,
Causes of emphysema –2
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Elastase degrades other proteins too – causes holes
in lungs
In healthy lungs, elastin not broken down as an
inhibitor present
In smokers, suggested oxidants in smoke
inactivate inhibitor
Elastase made by phagocytes to help them move
through body to sites of infection
When smoke, phagocytes gather in lungs so have
a lot of elastase and no inhibitor working
Treatment
Oxygen at home – sometimes15 hours per day
 Stop smoking
 Antibiotics
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Lung cancer
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Over 80% of lung cancer deaths caused by smoking and
¼ of all smokers die from it
Tobacco smoke contains carcinogens eg benzopyrene
which damage genes of epithelial cells which line lungs
Get mutant genes that which cause cells to divide by
mitosis out of control = tumour
Symptoms – persistent cough due to a reflex action to
obstruction, blood in sputum due to damage to tissues,
shortness of breath as obstruction, hoarseness due to
pressure on larynx or nerves supplying it
Wheezing
Tumour can metastase (break off and travel to another
part)
Lung cancer -2
Non small cell carcinoma – accounts for
70% bronchial carcinomas. Most commonly
linked to smoking
 Small cell carcinoma – arises from
endocrine tissues, rapidly growing and
aggressive
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Tuberculosis
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Infectious disease usually found in lungs ( bones or lymph
system also common)
Causes coughing, shortness of breath, fever and sweating
Kills 2 million each year
Caused by one of two rod shaped bacteria, Mycobacterium
tuberculosis or M. bovis, which infects cattle
Lungs develop opaque areas and large thick walled
cavities
Some people carry the bacteria but infection controlled by
immune system. Can be activated eg if weakened by AIDS
Spread by droplet infection, usually by close contact with
an infected person
At risk of TB
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In close contact with infected people
HIV sufferers
Suffering from conditions eg diabetes, silicosis
Being treated with immuno-suppresives eg
transplant patients
Malnourished
Working or residing in long term care facilities
Alcoholics, injecting drug users and / or homeless
From a country where TB is common
Prevention and control
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Vaccination – Bacille-Calmette-Guerin with
weakened M. bovis
Improved social conditions
Drugs eg isoniazid for 6-9 months or a drugs
cocktail. Kill active bacteria and those in cysts.
Can take a year
Contact tracing
Milk pasteurisation
Cattle checks by vets
Education
Better nutrition so healthy immune system
Pneumoconiosis
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Disease common among coalminers
Caused by breathing in the dust from coal over a
long period
Causes growth of nodules in bronchioles which
block the flow of air to the alveoli
Eventually leads to emphysema and bronchitis
Persistent coughing, breathlessness and production
of black sputum are symptoms
Reduce by sprinkling water on coal dust
Wear masks to filter air