Lung Disease

How does everyone remember the differences between lung diseases? The symptoms are all the same and no matter how much I revise/what I do I can't remember them! I don't have this problem with heart disease though.

On AQA I only do TB, Fibrosis, Asthma and Emphysema

Reply 1

zed963

Original post by xabsx

In asthma, an allergen causes inflammation, this can attract white blood cells to the area causing the release of histamine. When this occurs, the bronchi contract, reducing gas exchange and so you feel wheezy.

In emphysema, a particle irritate the alveoli, causing inflammation and attracts phagocytes which produce the enzyme to break down elastin so that alveolar recoil no longer occurs and thus maintaining a concentration gradient is difficult.

In pulmonary fibrosis what happens is that scar tissue forms and the epithelium of the lung things hence diffusion distance increases, reduction in tidal volume and the concentration gradient is harder to maintain, faster HR. The alveoli elasticity can also be damaged reducing alveolar recoil.

Reply 2

Megst

Asthma is due to an allergen being present e.g fungus. This triggers the production of histamine. This leads to the bronchi contracting, reducing airflow. The capillaries also secret fluid, and mucus is produced from the epithelium further reducing air flow. This lack of air flow leads to an asthma attack, coughing tc.

Emphysema is the result of damage to the alveoli and elastin. This damage can be due to smoke particles, air pollution etc. This damage to the elastin means that gas cannot be expelled as efficiently leading to difficulty breathing and the concentration gradient is more difficult to maintain. The elastin is also broken down by phagocytes from inflammation that break down the elastin further.This can lead to bluish tint the skin due to a lack of oxygen as well.

Tuberculosis is spread by droplets in the air and usually requires long term exposure. In primary infection the disease is only in the top portion of the lungs. Bacteria grow and divide and the immune system responds with white blood cells. This leads to inflammation of the lymph nodes. Sometimes the bacteria can remain and re emerge years later, once again growing and dividing in the upper portions of the lungs in post-primary infection. The difference is this time the bacteria is not so easy to break down and can damage lung tissue. This can lead to cavities in the lungs and scar tissue, which can be coughed up. Symptoms include weight loss, a cough etc.

Fibrosis is the formation of scar tissue on the lungs, leading to the lung becoming irreversibly thickened. This increases the diffusion pathway.This also reduces the elasticity of the lungs, once again meaning gases cannot be expelled as easily. This means the lungs are not efficiently ventilated. This can lead to shortness of breath due to less air being taken in, a cough due to the obstruction of the fibrosis tissue and weakness and fatigue to a lack of energy being produced from aerobic respiration.
Hope this helps

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