part_of starts_at ends_at muscle layer of prostatic urethra smooth muscle layer of prostatic urethra anatomical_structure EMAPA:32278 The smooth muscle layer of prostatic urethra (TS:28-28) is the smooth muscle layer towards the outside of the prostatic urethra. Part of the prostatic urethra, part of the urethra of male. Marked by proteins expressed by smooth muscle cells, such as smooth muscle alpha actin (Acta2). smooth muscle tissue smooth muscle of urethra TS28