amnion


Also found in: Thesaurus, Medical, Encyclopedia, Wikipedia.
Related to amnion: yolk sac, amnion nodosum

am·ni·on

 (ăm′nē-ən, -ŏn′)
n. pl. am·ni·ons or am·ni·a (-nē-ə)
A tough, thin membrane that forms a sac enclosing the embryo or fetus of a mammal, bird, or reptile. It is filled with a serous fluid in which the embryo or fetus is suspended.

[New Latin, from Greek amneion, variant of amneios, amnion, and from amnion, amnion, both from amnos, lamb; akin to Irish úan, Latin agnus, and Old Church Slavonic agnę, lamb.]

am′ni·ot′ic (-ŏt′ĭk), am′ni·on′ic (-ŏn′ĭk) adj.

amnion

(ˈæmnɪən)
n, pl -nions or -nia (-nɪə)
(Zoology) the innermost of two membranes enclosing an embryonic reptile, bird, or mammal. See also chorion
[C17: via New Latin from Greek: a little lamb, from amnos a lamb]

am•ni•on

(ˈæm ni ən)

n., pl. -ni•ons, -ni•a (-ni ə)
the innermost membrane of the sac surrounding the embryo in reptiles, birds, and mammals, enclosing the amniotic fluid.
[1660–70; < Greek amníon, derivative of amnós lamb (see yean)]
am`ni•ot′ic (-ˈɒt ɪk) am`ni•on′ic, adj.

am·ni·on

(ăm′nē-ən)
A sac of thin, tough membrane containing a watery liquid in which the embryo of a reptile, bird, or mammal is suspended. ♦ The watery fluid in the amnion is called amniotic fluid.
amniocentesis, amnion - Amniocentesis is formed by amnion, the innermost membrane enclosing a fetus, and Greek kentesis, "pricking."
See also related terms for mammal.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.amnion - thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)amnion - thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)
amniote - any member of the Amniota
mammal, mammalian - any warm-blooded vertebrate having the skin more or less covered with hair; young are born alive except for the small subclass of monotremes and nourished with milk
fetal membrane - any membrane that functions for the protection or nourishment or respiration or excretion of a developing fetus
sac - a structure resembling a bag in an animal
Translations

amnion

[ˈæmnɪən] n (amnions or amnia (pl)) [ˈæmnɪə]amnio

am·ni·on

n. amnios, saco membranoso que envuelve el embrión.
References in periodicals archive ?
in the blastocyst stage, during the formation of the chorion and the amnion.
Wrapped in his own skin, plunged into the darkness protected by an amnion, the artist is hidden yet exposed by the fissure.
Snoasis Medical Introduces, for Commercial Distribution, Biocover; the First Processed, Dehydrated and Sterilized Graft Composed of Amnion Tissue
R B Bigbie, J Schumacker, S F Swaim, K C Purohit, and J C Wright, Effect of amnion and yeast cell derivate on second intention healing in horses.
In addition, examination of the extremities showed strands of membranous tissue wrapped around the fingers and attached to the lower extremity, consistent with amnion bands (see Figure 5, A through D).
London, Jan 8 (ANI): Scientists at the Baylor College of Medicine in Houston, Texas, have shown that egg white can act as a sealant for the amnion, a membrane that surrounds developing foetuses.
A single nucleotide polymorphism in the matrix metalloproteinase-1 (MMP-1) promoter influences amnion cell MMP-1 expression and risk for preterm premature rupture of the fetal membranes.
Animal-model-causes of windowing-induced dysmorphogenesis (neural-tube defects and early amnion deficit spectrum) in chicken embryos.
Human placenta, chorion, amnion and decidua express different variants of corticotropin-releasing factor receptor messenger RNA.
failed to properly obtain, store, test and process the placentas as well as screen the suitability of the donors and the patients implanted with amnion tissue, the results of an inspection conducted in July, 2006 revealed.
Mechanical teratogenesis by amnion rupture, tearing, and adhering; tissue band adherence causing pressure necrosis and incomplete morphogenesis; or mechanical compression secondary to rupture of the chorion or the yolk sac.