The Cowper's glad, also known as the bulbourethral gland is responsible for producing pre-ejaculate fluid in the male reproductive system, as noted by Healthline. The purpose of the pre-ejaculate fluid is to make the environment of the urethra more hospitable for sperm and thus aid in reproduction.
First identified by anatomist William Cowper, each male has two bulbourethral glads located in the perineal pouch at the base of the penis. Their location is posterior and lateral to the urethra. In humans, each gland is approximately the size of a green pea and includes a 2.5-centimeter long duct which passes through the perineal membrane into the urethra.
When a male is sexually aroused, the Cowper glands act as exocrine glands, producing the mucous-like pre-ejaculate fluid and using it to cleanse and lubricate the urethra prior to the introduction of sperm. The pre-ejaculate fluid does this by neutralizing the acidity in the urethra as a result of the passage of urine. This, in turn, makes the urethra more hospitable for sperm in terms of the seed´s travel and survival.
The Cowper's glands are also partly responsible for the production and secretion of prostate-specific antigen (PSA), an enzyme which liquifies semen and allows it to swim through the urethra and into the female host more freely. The presence of PSA increases the chance of fertilization because it helps to dissolve cervical mucous to allow the sperm into the uterus to the egg.