part of part of male reproductive system external urethral sphincter reproductive structure male external urethral sphincter external urethral sphincter of male urethra male sphincter urethrae The external sphincter muscle of urethra (or sphincter urethrae membranaceae) surrounds the whole length of the membranous portion of the urethra, and is enclosed in the fasciæ of the urogenital diaphragm. They arch across the front of the urethra and bulbourethral glands, pass around the urethra, and behind it unite with the muscle of the opposite side, by means of a tendinous raphé. Wikipedia:External_sphincter_muscle_of_male_urethra bulboglandular male sphincter urethrae muscle FMA:19733 UBERON:0011379 male urethral sphincter muscle bulboglandular muscle NCIT:C52891 MA:0002273