prostate gland

Also from Answers.com... Vision Health A step-by-step "how-to" instruction.

A gland in male mammals surrounding the urethra at the base of the bladder that controls release of urine from the bladder and secretes a fluid which is a major constituent of semen.

A triangular body in men, the size and shape of a chestnut, that lies immediately in front of the bladder with its apex directed down and forward. It is found only in the male, having no female counterpart. The prostatic portion of the urethra extends through it, passing from the bladder to the penis. This organ contains 15–20 branched, tubular glands which form lobules. The gland ducts open into the urethra. Between the gland clusters, or alveoli, there is a dense, fibrous, connecting tissue, the stroma, which also forms a tough capsule around the gland, continuous with the bladder wall. Penetrating the prostate to empty into the urethra are the ejaculatory ducts from the seminal vesicles which are located above and behind the organ. The prostatic gland secretes a viscid, alkaline fluid which aids in sperm motility and in neutralizing the acidity of the vagina, thus enhancing fertilization. After middle age, the prostate is sometimes subject to new tissue growth, usually benign, that may result in interference with urine flow through the compressed urethra.

For more information on prostate gland, visit Britannica.com.

A gland in the male reproductive system that surrounds the urethra at the lower end of the urinary bladder. A large part of the fluids that make up semen comes from the prostate.