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amnion

amnion An inner cellular layer (epithelium) surrounding the fluid-filled embryo sac of reptiles, birds, and mammals. The wall of this sac has two layers of epithelium, with mesoderm and coelomic space between. The outer layer is usually called the chorion. The amnion and chorion develop as folds in the ectoderm and mesoderm which grow up around the sides of the embryo, eventually covering it. The amniotic fluid within the sac provides a liquid environment for the embryo, necessary for animals that reproduce on land. It may also cushion the mammalian embryo against distortion by maternal organs pressing on it. Sometimes the term ‘amnion’ is applied to the entire embryo sac.

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"amnion." A Dictionary of Zoology. . Encyclopedia.com. 22 Apr. 2017 <http://www.encyclopedia.com>.

"amnion." A Dictionary of Zoology. . Encyclopedia.com. (April 22, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amnion-0

"amnion." A Dictionary of Zoology. . Retrieved April 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amnion-0

amnion

am·ni·on / ˈamnēˌän; -ən/ • n. (pl. - or -ni·a / -nēə/ ) the innermost membrane that encloses the embryo of a mammal, bird, or reptile. DERIVATIVES: am·ni·ot·ic / ˌamnēˈätik/ adj.

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"amnion." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 22 Apr. 2017 <http://www.encyclopedia.com>.

"amnion." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (April 22, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/amnion

"amnion." The Oxford Pocket Dictionary of Current English. . Retrieved April 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/amnion

amnion

amnion Membrane or sac that encloses the embryo of a reptile, bird, or mammal. The embryo floats in the amniotic fluid within the sac. This sac usually ruptures shortly before birth to discharge the fluid, commonly referred to as ‘the waters breaking’. See also uterus

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"amnion." World Encyclopedia. . Encyclopedia.com. 22 Apr. 2017 <http://www.encyclopedia.com>.

"amnion." World Encyclopedia. . Encyclopedia.com. (April 22, 2017). http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/amnion

"amnion." World Encyclopedia. . Retrieved April 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/amnion

amnion

amnion A membrane that encloses the embryo of reptiles, birds, and mammals within the amniotic cavity. This cavity is filled with amniotic fluid, in which the embryo is protected from desiccation and from external pressure. See also extraembryonic membranes.

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"amnion." A Dictionary of Biology. . Encyclopedia.com. 22 Apr. 2017 <http://www.encyclopedia.com>.

"amnion." A Dictionary of Biology. . Encyclopedia.com. (April 22, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amnion-1

"amnion." A Dictionary of Biology. . Retrieved April 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amnion-1

amnion

amnion (am-ni-ŏn) n. the membrane that forms initially over the dorsal part of the embryo but soon expands to enclose it completely within the amniotic cavity.
amniotic (am-ni-ot-ik) adj.

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"amnion." A Dictionary of Nursing. . Encyclopedia.com. 22 Apr. 2017 <http://www.encyclopedia.com>.

"amnion." A Dictionary of Nursing. . Encyclopedia.com. (April 22, 2017). http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/amnion

"amnion." A Dictionary of Nursing. . Retrieved April 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/caregiving/dictionaries-thesauruses-pictures-and-press-releases/amnion

amnion

amnion (anat.) caul. XVII. — modL. — Gr. amníon, dim. of amnós lamb.

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"amnion." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 22 Apr. 2017 <http://www.encyclopedia.com>.

"amnion." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. (April 22, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/amnion-0

"amnion." The Concise Oxford Dictionary of English Etymology. . Retrieved April 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/amnion-0

amnion

amnion See AMNIOTIC.

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"amnion." A Dictionary of Earth Sciences. . Encyclopedia.com. 22 Apr. 2017 <http://www.encyclopedia.com>.

"amnion." A Dictionary of Earth Sciences. . Encyclopedia.com. (April 22, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amnion

"amnion." A Dictionary of Earth Sciences. . Retrieved April 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/amnion