Opening in prostatic sinus is
Vesiculae seminales and ampulla of ductus deferens, seen from the front. Dissection of the prostate showing the prostatic urethra. The prostatic ducts are seen opening into the prostatic sinus, which lies on either side of the urethral crest and seminal colliculus. ref - BDC vol2 pg 401-404 , semantischolar.org
Seminal vesicle
Ejaculatory ducts
Prostatic utricle
Prostatic ductules
Abdomen and pelvis