Correlative study of paraurethral anatomy.

This study was undertaken to identify with some precision the location of various paraurethral structures along the length of the urethra. The locations of four areas were identified. The intramural urethra (the area where this structure traverses the bladder wall) extends from the 0 to 15% of total urethral length. The midurethra extends from about 20 to 60% of total urethral length and is the region where one finds the striated urethral sphincter, posterior pubourethral ligaments, and vaginolevator attachments. The urogenital diaphragm with its compressor urethrae and urethrovaginal sphincter is found from 54 to 76% of urethral length. The distal urethra courses from 79 to 100% where the urethra passes between the vestibular bulbs and bulbocavernosus muscles. Some functional considerations of these findings are discussed.