The genome of the organism that produces the world's most lethal toxin has been revealed. This toxin is the major weapon in the genome of Clostridium botulinum: less than two kg is enough to kill every person on the planet.
pneumothorax. entry of air into the pleural cavity in sufficient quantity to cause collapse of the lung and consequent respiratory embarrassment. If it is unilateral there is a mediastinal shift with displacement of the heart to the other side of the chest. Breath sounds are absent from the affected side. Pneumothorax.
On the other hand, the two pleural layers tend to be separated by the elasticity of (1) the thoracic wall (directed outward) and (2) the lungs (stretched by inspiration). The pleural cavity, which is the potential space between the two layers, contains only a thin film of fluid. Air in the pleural cavity (pneumothorax) results in collapse of the lung. The pleura is supplied by adjacent arteries and nerves and has numerous lymphatics. Irritation of the parietal pleura causes pain referred to the thoraco-abdominal wall (intercostal nerves) or to the shoulder (phrenic nerve).