abnormal urinary bladder morphology herniated abdominal wall urinary bladder exstrophy MP:0013282 MPheno.ontology a herniation of the urinary bladder through an anterior abdominal wall defect; refers to congenital absence of a portion of the lower anterior abdominal wall and the anterior urinary bladder wall, with eversion of the posterior bladder wall through the defect, an open pubic arch, and widely separated ischia connected by a fibrous band ectopia vesicae everted urinary bladder exposed urinary bladder