The pressure is computed assuming an International standard sea-level pressure datum of 1013.25 hPa, and therefore is not necessarily the same as the aircraft's true altitude either above mean sea level or above ground level.he pressure is computed assuming an International standard sea-level pressure datum of 1013.25 hPa, and therefore is not necessarily the same as the aircraft's true altitude either above mean sea level or above ground level.
The term pleurisy (pleuritis) is inflammation or infection in the pleural space around the lungs. Pyothorax also known as empyema of the pleural cavity is the presence of pus in the pleural cavity between the layers of the pleural membrane Py/o-Pus.
The outer pleural layer is known as the parietal pleura and lines the inside of the chest cavity around the lung. The inner pleural layer is attached to the lungs and is known as the visceral pleura.The pleural cavity is the space between the two pleural layers and it contains approximately 10 to 20ml of thin serous fluid known as the pleural fluid.owever, the pain may radiate or refer to surrounding areas. 1  If the parietal pleura lying in the area of the upper six ribs is inflamed, it causes localized pain (upper chest pain). 2  When the pleura behind the lower ribs and outer parts of the diaphragm are inflamed, the pain may be referred to the upper abdomen.