Introduction

Functions of the Prostate Gland. The prostate gland provides the following functions:

• The glandular cells produce a milky fluid, and during sex the smooth muscles contract and squeeze this fluid into the urethra. Here, it mixes with sperm and other fluids to make semen.
• The prostate also secretes another substance that may have antibacterial properties.
• The prostate gland also contains an enzyme called 5 alpha-reductase that converts testosterone to dihydrotestosterone, another male hormone with as a major impact on the prostate.

Changes During the Lifespan. The prostate gland undergoes many changes during the course of a man's life. At birth, the prostate is about the size of a pea. It grows only slightly until puberty, when it begins to enlarge rapidly. It reaches normal adult size and shape, about that of a walnut, when a man is in his early 20s. The gland generally remains stable until about the mid-40s, when, in most men, the prostate begins to grow again through a process of cell multiplication.

Hormonal changes also occur in the prostate gland. Testosterone levels fall while dihydrotestosterone remain at normal levels.