Sperm leaves the male body by means of ejaculation from the male sexual organ, the penis. Here's a breakdown of how that happens:
- A male who has reached puberty will produce millions of sperms cells daily. Each sperm cell is only around 0.05 millimetres long.
- Sperm develop in the testicles in tiny tubes known as somniferous tubules. Cells that have been there since birth combine with testosterone and other hormones and become sperm cells.
- The cells divide and change their shape until they have a head and a tail, like tadpoles. The head contains the genes that are passed on from a parent to a child.
- The sperm use their tails to move into the epididymis where their development continues for around 4-6 weeks.
- The sperm then move to the sperm duct where the seminal vesicles and prostate gland make a whitish fluid known as seminal fluid which, when a male is sexually excited, mixes with sperm to form semen.
- At this time tissues in the penis fill with blood and it becomes erect.
- When the now erect penis is stimulated the muscles around the reproductive organs contract and semen is forced through the duct system and urethra in the process known as ejaculation.
- Up to 500 million sperm are contained in each ejaculation.