Lung Diseases

Description of Fibrosis, Emphysema, Asthma and Pulmonary Tuberculosis

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1) Foreign particles (generally caused by smoking or long-term exposure to air pollution) get trapped in alveoli

2) Inflammation is caused, attracting phagocyte which break down elastin; a protein found in the alveoli walls

3) Alveoli unable to recoil to expel air, so it remains in the alveoli

4) Alveoli walls detroyed, reducing surface area, thus gaseous exchange.

5)Symptoms: shortness of breath, blueish skin tinge, coughing/wheezing and increased breathing rate

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  1. Usually caused by an allergic reaction to pollen or dust.
  2. The reaction causes the airway to become irritated and therefore inflamed
  3.  Mucus is produced when the smooth muscle of the bronchiole lining contracts
  4. The mucus causes consriction of the airway, severely reducing air flow in and out of the lungs
  5. This means less oxygen enters the alveoli
  6. Symptoms: Wheezing/ coughing and shortness of breath 
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  1. Sometimes caused by infection or expossure to substances such as dust
  2. This causes the formatio of scar tissue, which is thicker and less elastic than normal lung tissue
  3. The lungs aren't able to expand as much, so can't hold as much air (tidal volume is reduced)
  4. Rate of gaseous exchange decreaes as there is a longer diffusion pathway
  5. Symptoms: Shortness of breath, dry cough, chest pain, fatigue and weakness
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Pulmonary Tuberculosis

  • TB is transmitted by droplet infection (coughs and sneezes release tiny droplets of saliva and mucus)
  • There tends to be a higher infection rate in areas of poor hygiene and high population density
  • When the TB bacteria goes inside the body, immune system cells form small, hard lumps around the bacteria known as tubercules.
  • The tubercule causes the infected tissue to die, which damages the gaseous exchange surface
  • Tidal volume decreases
  • TB also causes fibrosis, reducing tidal volume further
  • Some bacteria may survive, and if it enters the blood stream can spread to other parts of the body, proving fatal.
  • Symptoms: Coughing blood and mucus, chest pains, shortness of breath, fatigue, fever and loss of weight
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