prostatic ducts prostatic ducts the prostatic ducts (or prostatic ductules) open into the floor of the prostatic portion of the urethra, and are lined by two layers of epithelium, the inner layer consisting of columnar and the outer of small cubical cells. prostatic ductsdetailsidentifierslatinductuli prostaticita98a09.3.08.019ta23652fma71651anatomical terminology small colloid masses, known as amyloid bodies are often found in the gland tubes. they open onto the prostatic sinus.