bulbourethral

Bulbourethral glands, also called Cowper's glands, are a pair of small exocrine glands in the male reproductive system. They lie in the deep perineal pouch within the urogenital diaphragm, on either side of the membranous part of the urethra, often described as being posterolateral to the base of the penis. Each gland is roughly pea-sized, with ducts that pass through the perineal membrane and open into the proximal portion of the spongy (penile) urethra, near the bulb.

Their primary function is to secrete a clear, viscous mucus during sexual arousal. The secretion lubricates the urethra for the passage of semen and helps neutralize residual acidity of urine in the urethral lumen, protecting sperm. The fluid is commonly referred to as pre-ejaculate. In some individuals, the secretion may contain sperm, and thus it can contribute to fertility.

Clinically, bulbourethral glands can be involved in infections (bulbourethritis), formation of cysts, or, rarely, neoplasms. Ductal obstruction or inflammation may affect urethral discharge and be evaluated in urologic assessments. The glands are generally considered part of the male accessory reproductive glands, and the eponymous term Cowper’s glands reflects historical naming in anatomy.