from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. A caplike structure at the anterior end of a spermatozoon that produces enzymes aiding in egg penetration.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. A structure forming the end of the head of a spermatozoon.

from The Century Dictionary and Cyclopedia

  • n. In cytology, the body which forms the extreme anterior portion of the spermatozoön. Von Lenhossek, 1897.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a process at the anterior end of a sperm cell that produces enzymes to facilitate penetration of the egg


acro- + -some3.
(American Heritage® Dictionary of the English Language, Fourth Edition)
acro- + -some (Wiktionary)


  • In order to accomplish this the head of each sperm called the acrosome contains a packet of shell-dissolving enzymes—released when contact with the egg is made.

    Getting Pregnant

  • As researchers from the University of Illinois explain it, normal sperm are composed of a cap-like structure that surrounds the anterior end of the sperm head called the acrosome.

    NYDN Rss

  • The acrosome is a large membrane-limited granule that overlies the nucleus of mature sperm

    PLoS ONE Alerts: New Articles

  • The acrosome is the packet of enzymes in the sperm’s head that produces enzymes to facilitate penetration of the egg.

    A Baby at Last!

  • The acrosome reaction is the chemical change that enables a sperm to penetrate an egg.

    A Baby at Last!

  • However, the amount of Viagra at concentrations equivalent to what a man would have thirty minutes after taking the maximum recommended 100 milligram dose leads to early activation of the acrosome reaction.

    A Baby at Last!

  • If sperm undergo the acrosome reaction too early, before they contact the egg, they are incapable of fertilization.

    A Baby at Last!

  • So if the majority of sperm undergo the acrosome reaction on exposure to Viagra, the drug may significantly impair their fertilizing potential.

    A Baby at Last!

  • They found that while the Viagra-bathed sperm became more active, they also suffered damage to the structure at their heads known as the acrosome.

    Archive 2008-08-01

  • Only after the capacitation is completed can the spermatozoa respond to the oocyte interaction with the exocytosis of acrosome content, the acrosome reaction (AR).

    BioMed Central - Latest articles


Log in or sign up to get involved in the conversation. It's quick and easy.