ABSTRACT
I. INTRODUCTION The urinary sphincter is a term applied to the structures in the urethra that contribute to the function of opening and closing of the urethra. Anatomically, several structures have been identified that participate in the “sphincter” function of the urethra. Although the focus of this chapter is not on the detailed description of these structures, their mention is needed to allow the discussion on the pathophysiological causes of sphincteric failure.
