Lung disorders Unit 4C section C.3 CSE November 2006

Bronchitis 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 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, in UK die each year Diagnosis by lung measurements eg peak flow, vital capacity

Chronic bronchitis 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 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 Kills 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 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 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

Lung cancer 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

Tuberculosis 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 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 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 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