[TA] relatively thin inner coat of smooth (involuntary) muscle bundles, both circularly and longitudinally arranged and separated from the epithelium by a thin vascular stroma of fibroelastic connective tissue, which are continuous inferiorly with those of the intermediate urethra and peripherally with the fibromuscular tissue of the prostate, including a relatively thick, troughlike layer of skeletal (voluntary) muscle that ascends the anterior aspect of the prostatic urethra to the neck of the bladder as part of the external urethral sphincter; proximal (superior) to the seminal colliculus, which bears the openings of the ejaculatory ducts, the circular layer of smooth muscle is especially prominent as a continuation of the internal urethral sphincter of the intramural or preprostatic part of the urethra.external urethral sphincter of male, internal urethral sphincter. SYN: tunica muscularis partis prostaticae urethrae masculinae [TA], muscular coat of intermediate part of male urethra*, muscular coat of prostatic urethra.