yolk sac

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yolk sac

n.
A membranous sac attached to the embryo and enclosing the yolk in egg-laying vertebrates. In humans and other placental mammals, it functions as the circulatory system for the embryo before internal circulation begins.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

yolk sac

n
1. (Zoology) the membranous sac that is attached to the ventral surface of the embryos of birds, reptiles, and some fishes and contains yolk
2. (Zoology) the corresponding part in the embryo of mammals, which contains no yolk
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

yolk′ sac`


n.
an extraembryonic membrane that encloses the yolk of eggs.
[1860–65]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.

yolk sac

A sac attached to the gut of an embryo that encloses the yolk in bony fish, sharks, reptiles, mammals, and birds. In most mammals, the yolk sac functions as part of the embryo's circulatory system before the placenta develops.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.yolk sac - membranous structure that functions as the circulatory system in mammalian embryos until the heart becomes functionalyolk sac - membranous structure that functions as the circulatory system in mammalian embryos until the heart becomes functional
sac - a structure resembling a bag in an animal
2.yolk sac - membranous structure enclosing the yolk of eggs in birds, reptiles, marsupials, and some fishes; circulates nutrients to the developing embryo
sac - a structure resembling a bag in an animal
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
Percentage of survival at hatching (Sh) and proportion of live yolk-sac larvae (Ll) obtained from spawns collected 48 h after injection of the LHRHa-treated groups.
In all groups, a strong linear correlation (above r2=0.9) was found between alevin weight and degree-days, and yolk-sac weight and degree-days.
Effect of photoperiod on growth and efficiency of yolk-sac utilization in alevins of brook trout (Salvelinus fontinalis).
(1,18) Pseudomonas aeruginosa has also been described in bustards with yolk-sac infection, meningitis and septicemia, (1) and more sporadically in dermatitis, panopthalmitis, osteomyelitis, hemorrhagic diarrhea, and stomatitis.
In this study, the eggs and yolk-sac larvae came from a fertilization experiment, and that origin confirmed their species identity.
Moreover, C18: 2n-6, C18: 3n-3, C20: 1n-9, C20: 2n-6, C20: 3n-6 reduced from fertilized eggs to absorbed yolk-sac larvae.
Influence of salinity on embryogenesis, survival, growth and oxygen consumption in embryos and yolk-sac larvae of the Nile tilapia.
With translucent bodies, the only solid-looking parts of the alevin are the steel-gray eye and the poppy-colored yolk-sac. In keeping with the wisdom of nature, by the time the alevins have absorbed the nutrients from the yolk-sac, the river has warmed, luring the silvery fry from their gravel cradles.
Thus the 2 yolk-sac isolates are antigenically very similar if not identical.
But the Industrial Revolution achieved these feats in rather the fashion of a fetal bird in the egg, by drawing down the world's yolk-sac of fossil fuels, high grade ores, topsoil, and perhaps even its peoples' accumulated cultural discipline and moral/aesthetic traditions.
The differential diagnosis of our case includes metastasis of ACC from another site,[14] primary or metastatic ACC-like carcinoma,[1,3] and a reticular variant of a yolk-sac tumor.[15] Metastasis of ACC from another site could be excluded only after careful clinical examination, which revealed no tumor elsewhere.
Several deformities, including coiled larvae, cardiac edema/arrythmya, yolk-sac edema, and several varieties of spine flexion, were also described as a result of hydrocarbon-induced stress (Vines et al., 2000; Williams et al., 2003; Incardona et al., 2004, 2009).