So where does a rib cage " leak". If it does leak ? How can one use the diaphragm to breath? When on enters the thoracic cavity with a knife why does air rush in? Thanks.
Lungs function exactly like a bellows. External motive force is applied in one direction and air goes out. Applied in the opposite direction, air goes in.
I pneumo-thorax s simply a hole in the chest (possibly the lung(s) also, but not necessarily)allowing air to enter the chest (not the lungs). The first diaphragm cycle pulls some air into the lung and some into the chest. The difference between pre-pneumo and post-pneumo results in some lung deflation. As more cycles go by more lung deflation results unless the hole is plugged.
Generally for our purposes we penetrate one or both lungs and damage pressurized blood vessels which also begins to pressurize the chest which deflates the lung(s) some more. Even an extreme pneumo in which both lungs are extremely damaged and instantly are deflated or completely broken apart into red soup and the heart remains intact to pump the chest full does not guarantee a DRT. The animal still can remain functional for a few to maybe ten seconds after the wound, although with each second passing the capability is decreasing . With less extreme pneumos, the animal can remain functional from minutes to hours. With competent medical help and the right tools available, a pneumo can be reversed provided lung damage is not too severe.
A pneumo can also result from a rib breaking and puncturing the lung(s) without a hole in the chest.
SOmeone above mentioned lungs as muscle. They are not muscle. They are highly vascular sacs that intake and expel air in response to increasing or decreasing chest volume.
