Lung Diseases

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Pulmonary Fibrosis

·         This occurs when scar tissue replaces the epithelium and this become thick (irreversible). So people who have this find there o2 intake is low (The alveoli needs a thin linings not thick, this reduces the amount of O2 which is diffused). The lungs need elasticity to it can inflate and deflate, so it makes the person with fibrosis hard to breathe and ventilate the lungs.
- Shortness of breath, especially when exercising as a large amount of air space is needed, the s[ace is being used by the fibrous tissue. So this means less air is taken in (so low O2), also the diffusion pathway has increased so oxygen going to blood is slower, making ventilation difficult. So it is hard to maintain a diffusion gradient.
- Chronic dry cough the tissue acts like an obstruction in the lungs, so the body’s natural reflex is to cough it up. But since the tissue cannot be moved it means nothing is coming out and so the cough is ‘dry’.
- Pain and discomfort in the chest, damage from the amount of fibrosis tissue and the constant coughing put pressure on the lungs.
- Weakness and fatigue, as there is reduced intake of O2 so the energy which is released is not released as there is not enough O2, so the person will be feeling constantly tired.


·         Asthma affects about 10% of the world’s population, allergens which stimulate these, they are like pollen and animal fur etc. they can be made worse by air pollutants (sulphur dioxide, nitrogen oxides and ozone), exercise, cold air and infection etc. Each of these makes WBCs come to the site and they release chemical called histamine, these causes:
- The lining of the airways become inflamed.
- The cells of the epithelium become much thicker at producing mucus than normal.
- Fluid leaves the capillaries and in to the airways.
- The muscle around the airways contract and therefore leaves little space for air to pass.

·         Therefore it makes it harder to


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