An overview of the prostate from a young boy. The curved lumen in the middle of the section is the prostatic urethra (the mucosa is folded). Posterior to the urethra there are two round holes: the right and left ductus ejaculatorius. The colliculus seminalis bulges into the urethra posteriorly.  A bit of the muscle layers and mucosa of the rectum is seen in the lower part of the picture.