Ok the thing is there is no air inside the thorax. The only air is inside the lungs. There isn’t any empty space just floating around. Only when there’s a hole punched in the cavity does the area have space around the lung because they collapse. When you breathe the expansion is in the ribs and diaphragm. If the lungs just got smaller and bigger when you breathe then there wouldn’t need to be any movement of the chest at all.I’m just skeptical of how high the lungs come up behind the scapula. Ol buddy throws about 180 psi to a Deers lungs and hell yeah they expand and fill the entire thoracic cavity. But is that the normal pulmonary function within a whitetail? I’m asking because I’d dont know.