sperm
The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.
DEFINITION:
- sperm
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The semen or testicular secretion; the male sex cell, also known as spermatozoon (singular) or spermatozoa (plural), responsible for fertilization of the female ovum. Sperm are microscopically tiny, measuring 0.002 inch (0.05 mm) in length.
Sperm are produced within the seminiferous tubules of the testes by a process known as spermatogenesis. The production and development of sperm is dependent on the male sex hormone testosterone and on gonadotropin hormones produced by the pituitary gland. Sperm production commences at puberty.
The original cell from which a sperm develops contains 46 chromosomes, including the XY pair of male sex chromosomes. By a process of cell division, the number of chromosomes in the sperm is halved to 23, including either the X or the Y from the original pair of sex chromosomes. This X or Y is responsible for determining the sex of an embryo that develops after fertilization of the ovum by the sperm.
The final stage of spermatogenesis takes place in the epididymis, where the sperm grow tails that will propel them through the woman's reproduction tract after ejaculation during sexual intercourse.
Used in 3 Article translations
Used in 3 Article translations