In addition to the testes and ducts, the male reproductive system contains three sets of glands: the seminal vesicles, the prostate gland, and the bulbourethral glands. The two seminal vesicles secrete a thick, clear fluid that lubricates and nourishes the sperm. the prostate gland secretes a milky, alkaline that balances the acidity of any traces of urine in the urethra and helps protect the sperm from the natural acidity of the vagina. The to bulbourethral glands secrete only a few drops of fluid into the urethra, during sexual arousal. The fluid may help lubricate the urethra, helping sperm move through. It