abnormal respiratory system morphology abnormal pleural cavity morphology 2014-03-19T21:58:09Z MP:0012684 MPheno.ontology abnormal intrapleural space morphology abnormal pleural space morphology any structural anomaly of the potential space between the two pleurae (visceral and parietal) of the lungs; the pleural cavity, with its associated pleurae, aids optimal functioning of the lungs during breathing; it normally contains a thin film of serous fluid which lubricates the opposed pleural membranes so that they can glide smoothly against one another during ventilation csmith