Bladder and its anatomical relationship with the genital system in a 3-year-old boy. This drawing shows the bladder at the pelvic level and its relationship to the genital system in the little boy on a 3/4 view. The ureters (in yellow ocher) terminate in the posterior wall of the bladder (in orange) with an orifice at each end of the bladder trigone. Below the bladder is the prostate (in pinkish beige) and behind the seminal vesicles and vas deferens. The vas deferens bypass the bladder from the back and the top then the front and the bottom to the testicles (white mother-of-pearl color). The urethra in boys starts from the bottom of the bladder, passes through the prostate and ends in the penis through the urinary meatus.