The urethra in the filling phase

showing differences in the two sexes. Divisions into internal and external sphincter are functional rather than anatomic. The antomy is still debatable.Note the male has a much higher urethral pressure and also a contribution from the prostate. hence the voluntary muscles of the levator ani (pelvic floor) are more crucial in providing continence in the female especially if the urethra has been moved outside the abdominal cavity by childbirth.