Lung Disease

HideShow resource information

Tuberculosis is Caused by one of two species of rod-shaped bacteria:Mycobacterium tuberculosis or Mycobacterium bovis. The Symptoms of Pulmonary TB consist of: Persistent cough, Tiredness, Loss of Appetite which leads to weight loss, As the disease develops, fever and coughing up of blood may be seen.The Transmission of TB occurs through the air by droplets, which are released into the air when people cough, sneeze, laugh or talk. Mycobacterium tuberculosis is a resistant bacterium which can survive several weeks once the droplets have dried. Normally close contact with an infected person over a period of time is generally required to spread the disease. TB can also spread from cattle to humans because Mycobacterium bovis also infects cattle. The milk form theses cows may contain the bacterium. Some groups of people are at greater risk of contracting TB, these include:Are living in close contact with infected individuals over long periods of time, Work or reside in long-term care facilities where relatively large numbers of people live close together, Are from countries where TB is common, Those with reduced immunity, (young/old, undergoing treatment, malnourished, homeless) Once Mycobacterium tuberculosis has been inhaled by someone who is not immune, this infection follows this course:The bacteria grow and divide within the upper regions of the lungs, where there is a plentiful O2 supply. Body’s immune system responds and white blood cells accumulate at the site of infection to ingest the bacteria. This leads to inflammation and the enlargement of the lymph nodes that drain that area of the lungs. This is called Primary Infection this usually occurs in children.In a healthy person there are a few symptoms, if any, and the infection is controlled within a few weeks. However some bacteria remain.Many years later these bacteria may re-emerge to cause a second infection of TB. This is called post-primary TB and typically occurs in adults. This infection also arises in the upper regions of the lungs and is not so easily controlled. The bacteria destroy the tissue of the lungs. This results in cavities and where the lung repairs itself, scar tissue.The sufferer coughs up damaged lung tissue containing the bacteria, along with blood. Without treatment TB spreads to the rest of the body and can be fatal.Prevention of TB can be with a vaccine, better housing, better TB education, improved health facilities and treatment, better nutrition to prevent weakening of immune system.

Pulmonary Fibrosis

Pulmonary fibrosis arises when scars form on the epithelium of the lungs causing them to become irreversibly thickened. Therefore the diffusion distance for gas exchange has increased so gas exchange is less efficient. So only a smaller volume of gas can be exchanged.The fibrosis reduces the elasticity of the lungs.The Fibrosis makes it difficult to breathe out and therefore ventilate the lungs.The effects of fibrosis on lung function are as follows: Shortness of breath, especially when exercising is due to a considerable volume of the air space within the lungs being

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Health, illness and disease resources »