The verumontanum is a smooth filling defect along the posterior wall of the prostatic urethra. The membranous urethra passes through the urogenital diaphragm and is the shortest segment at 1-1.5 cm long. The paired Cowper glands lie within the urogenital diaphragm and their ducts extend about 2 cm to enter the bulbous urethra. The bulbous urethra begins below the urogenital diaphragm and has a conical widening called the "cone" just distal to the bulbomembranous junction, though an indentation from the bulbospongiosus muscle here should not be confused