Intrapleural tension may be defined as the force which maintains expansion of the lungs under normal conditions. From another point of view it may be considered as a potential negative pressure within the pleural cavities dependent on, and caused by, the normal elasticity and contractability of the lungs.
I have studied the changes in normal intrapleural tension produced by various pathologic conditions, as well as the mediastinum of man and dog in order to determine: (1) whether there is any essential difference in the mobility of the mediastinum of man and dog, (2) whether the stability and relative strength of the structure in the two instances are comparable, (3) whether a change in the intrapleural tension of one side produces an equal change on the opposite side and, if so, by what type of mechanism, (4) whether it is possible to produce a unilateral pneumothorax in a dog, and (5)
SNYDER JW. STUDIES IN INTRAPLEURAL TENSION. Arch Surg. 1924;8(1):364-393. doi:10.1001/archsurg.1924.01120040375020