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Spermatozoa (sperm)

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A group of sperm, with detail of a single sperm.

Spermatozoa (sperm) are the male sex cells that carry genetic material. They are so tiny that they can't be seen without a microscope. One ejaculation usually contains between 20 million and 600 million sperm.

Sperm have an oval head, a short middle, and a long tail. They move by whipping their tails. A sperm fertilizes an egg (ovum) by breaking through the membrane that surrounds the egg.

Sperm develop in the testicles. They are added to semen before ejaculation.

Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.