ABSTRACT
I. INTRODUCTION The structure and function of an organ can be understood best in the context of its embryogenesis. Hence, it is surprising that relatively little is known about the development of the urinary sphincter. In reviewing numerous embryology texts, there are extensive discussions of renal, ureteral, bladder, and even prostatic development, but virtually nothing is written about the urinary sphincter. Furthermore, the limited published literature includes both animal and human studies, with this distinction being important because of the variations in voiding purposes and patterns in differing species. In addition, few of the studies beyond simple histology are gender-specific and the recent recognition of high-pressure voiding in human male neonates suggests that there may be gender-specific development of the sphincter.
