Whitish viscous fluid emitted from the male reproductive tract that contains sperm and liquids (seminal plasma) that help keep them viable. Sperm cells, produced by the testes in humans, represent 2–5% of semen volume; fluids from tubules, glands, and storage areas of the reproductive system bathe them as they travel down, nourishing them, keeping them motile, or participating in certain chemical reactions. During ejaculation, liquids from the prostate gland and seminal vesicles dilute the sperm and provide a suitable, slightly alkaline environment. An average ejaculation of a human male expels 0.1–0.3 cu inches (2–5 ml), containing 200–300 million sperm.
Variants of SEMEN
semen or seminal fluid
This entry comes from Encyclopædia Britannica Concise.
For the full entry on semen, visit Britannica.com.
Seen & Heard
What made you look up semen? Please tell us what you were reading, watching or discussing that led you here.