What is Pneumothorax?~20marks

The meaning of Pneumothorax:(website at the bottom)
in chinses:氣胸

In medicine (pulmonology), a pneumothorax, or collapsed lung, is a potential medical emergency caused by accumulation of air or gas in the pleural cavity. A pneumothorax can occur spontaneously, or as the result of disease or injury.

It most commonly arises:

Spontaneously (most commonly in tall slim young males and in Marfan syndrome)
Following a penetrating chest wound
Following Barotrauma to the lungs
It may also be due to:

Chronic lung pathologies including emphysema, asthma
Acute infections
Chronic infections, such as tuberculosis
Cancer
Rare diseases that are unique to women such as Catamenial pneumothorax (due to endometriosis in the chest cavity) and lymphangioleiomyomatosis (LAM).
Pneumothoraces are divided into tension and non-tension pneumathoraces. A tension pneumothorax is a medical emergency as air accumulates in the pleural space with each breath. The increase in intrathoracic pressure results in massive shifts of the mediastinum away from the affected lung compressing intrathoracic vessels. A non-tension pneumothorax by contrast is a less severe pathology because there is no ongoing accumulation of air and hence no increasing pressure on the organs within the chest.

The accumulation of blood in the thoracic cavity (hemothorax) exacerbates the problem, creating a hemopneumothorax

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**if you want to see the photoes of it , go to this website:**

1.)http://upload.wikimedia.org/wikipedia/commons/2/2f/Pneumothorax_CXR.jpg

2.)http://upload.wikimedia.org/wikipedia/commons/5/57/Pneumothorax_CT.jpg

3.)http://upload.wikimedia.org/wikipedia/commons/8/8f/Sucking_chest_wound_mechanics.jpg