Male urinary tract infection. Illustration of the male urinary system with a background of bacteria. The two kidneys (upper right) filter waste products from the blood. The waste products are transported as urine to the bladder (red, lower centre) via the ureters (yellow tubes). Urine is stored in the bladder until it exits the body via the urethra (bottom left). Just below the bladder is the prostate gland (pink), which secretes a fluid that forms part of the semen.