part_of starts_at ends_at bladder-urethra transition zone mesenchyme of bladder-urethra transition zone anatomical_structure EMAPA:36334 The mesenchyme of bladder-urethra transition zone (TS:22-TS:28) is the mesenchyme surrounding the epithelium in the zone or region where the bladder neck meets the urethra/pelvic urethra. It is similar to transitional zones in other organs, such as the female cervix and the Z-line in the oesophagus. It is located close to where the nephric duct attaches to the urogenital sinus. Part of the bladder-urethra transition zone and part of the urogenital sinus and part of the urinary system. Use this term to annotate expression in the mesenchyme where the bladder neck meets the pelvic urethra, when the tissue cannot be identified as being either part of the bladder or part of the pelvic urethra. TS22 TS28