Skip Navigation

Overview of the Male Reproductive System

Author(s): Center for Educational Outreach, Baylor College of Medicine.

Accessory Glands

Accessory glands add secretions to the semen. A pair of seminal vesicles contribute about 60% of the total volume of the semen, a thick, yellowish, alkaline fluid. Semen contains sugar fructose, which provides most of the energy used by the sperm. 

The prostate gland secretes its products directly into the urethra through several small ducts. This fluid is thin and milky, and contains anticoagulant enzymes and citrate, a sperm nutrient. 

The bulbourethral glands, also called the Cowper’s glands, secrete a clear mucus that neutralizes any acidic urine remaining in the urethra before ejaculation.