acrosome

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Related to Acrosomes: Acrosome reaction, Acrosomal process

acrosome

 [ak´ro-sōm]
the caplike, membrane-bound structure covering the anterior portion of the head of a spermatozoon; it contains enzymes involved in penetration of the ovum.
Acrosome of a spermatozoon. From Applegate, 2000.
acrosome reaction changes in the spermatozoon that result in development of perforations in the acrosome, allowing release of enzymes that facilitate fertilization.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

ac·ro·some

(ak'rō-sōm),
A caplike organelle or saccule derived from Golgi elements that surround the anterior two thirds of the nucleus of a sperm. Enzymes contained within this structure probably facilitate the sperm's penetration of the zona pellucida of the oocyte.
Synonym(s): acrosomal cap, head cap
[acro- + G. soma, body]
Farlex Partner Medical Dictionary © Farlex 2012

acrosome

(ăk′rə-sōm′)
n.
A caplike structure at the anterior end of a spermatozoon that produces enzymes aiding in egg penetration.

ac′ro·so′mal (-sō′məl) adj.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

Acrosome

A membrane-bound cap-like structure at the head of a spermatozoon that contains lytic enzymes—e.g., acrosin hyaluronidase—which degrade the ovum’s zona pellucida, allowing the penetration of one sperm.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

acrosome

Reproduction biology A membrane-bound cap-like structure at the head of a spermatozoon that contains lytic enzymes–acrosin hyaluronidase which degrade the outer coat of the egg and allow the penetration of one sperm. See Acrosome reaction. Cf Capacitation.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

ac·ro·some

(ak'rō-sōm)
A caplike organelle that surrounds the anterior two thirds of the nucleus of a sperm. Within this cap are enzymes that are thought to facilitate entry of the sperm into the oocyte.
[acro- + G. soma, body]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

acrosome

A tiny sac or double membrane in the head of a SPERMATOZOON that contains the digestive enzymes needed to break down the protective cell membrane of the egg (OVUM) and allow penetration. Release of these enzymes is called the acrosome reaction.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
Acrosomeclick for a larger image
Fig. 8 Acrosome . Head of a typical mammalian sperm.

acrosome

a membrane-bound sac derived from the GOLGI APPARATUS, located at the tip of the sperm. The acrosome plays an important role in fertilization. It contains enzymes that, when the sac ruptures upon contact with the egg, aid in penetration of the egg membrane, so allowing transfer of the sperm nucleus to the egg cell. See Fig. 8 .
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
The zebra mussel acrosome consists of a prominent acrosomal filament and an electron-dense basal region.
Acrosome morphology in hormone-supplemented culture for 6, 18, and 24 h is shown in Figure 1B.
In Mytilus, a family of lysin proteins present in the sperm acrosome are involved in degrading the egg vitelline envelope during sperm entry (Takagi et al.
The nuclear filament is extended through the pore and down to the vitelline layer, where the acrosome digests a hole for it to enter and fuse with the egg.
The acrosomal contents were more tightly packed in the anterior region of the acrosome than in the posterior region.
The major sites of polymerized MFs include the sperm acrosome, the egg microvilli, and the fertilization cone.
The sperm of Callochiton castaneus (described by Hodgson et al., 1988) has a bullet-like nucleus extending into a long nuclear filament tipped by a minute acrosome, but it has retained a relatively unspecialized mid-piece (Figs.
The maximal sperm acrosome integrity of 20.0 mm was observed in taurine group.
Additionally, ACRI values in cm presented a higher percentage than in cp, and those were greater than pm, similar to other reports in which the normal acrosomes percentage was higher in maternal line than in paternal lines (ROBINSON & BUHR, 2005; WYSOKINSKA & KONDRACKI, 2013).
The data on the effect of glutathione in extender on percentage of live (with intact acrosomes) Sahiwal bull spermatozoa are illustrated in Figure 1D.
Watson, "Use of a Giemsa stain to detect changes in acrosomes of frozen ram spermatozoa," Veterinary Record, vol.