Anatomy, Zoology. the innermost of the embryonic or fetal membranes of reptiles, birds, and mammals; the sac in which the embryo is suspended.
Zoology. a similar membrane of insects and other invertebrates.
noun (pl) -nions, -nia (-nɪə)
the innermost of two membranes enclosing an embryonic reptile, bird, or mammal See also chorion
1660s, Modern Latin, from Greek amnion “membrane around a fetus,” said to be originally “bowl in which the blood of victims was caught” [Liddell & Scott], which is variously said to be of unknown origin, from ame “bucket,” or a diminutive of amnos “lamb.”
amnion am·ni·on (ām’nē-ən, -ŏn’)
n. am·ni·ons or am·ni·a (-nē-ə)
The thin, membranous sac filled with a serous fluid in which the embryo or fetus is enclosed and suspended in the uterus. Also called amniotic sac.
am’ni·ot’ic (-ŏt’ĭk) or am’ni·on’ic (-ŏn’ĭk) adj.
A thin, membranous sac filled with a watery fluid (called the amniotic fluid) in which the embryo or fetus of a reptile, bird, or mammal is suspended during prenatal development. Also called amniotic sac.
Anatomy, Zoology. the innermost of the embryonic or fetal membranes of reptiles, birds, and mammals; the sac in which the embryo is suspended. Zoology. a similar membrane of insects and other invertebrates. Historical Examples amnion cavity: a tube-like insinking from the ventral plate of the embryo, extending cephalad. Explanation of Terms Used in Entomology John. […]
of, relating to, or having an . Contemporary Examples Chronic uncertainty surrounds children living under occupation like amniotic fluid. More on Palestinian Children Emily L. Hauser July 26, 2012 Historical Examples Intra-uterine amputation by constriction of amniotic bands sometimes occurs (Figs. 168, 169). Manual of Surgery Volume Second: Extremities–Head–Neck. Sixth Edition. Alexander Miles The constant […]
Informal. . noun short for amniocentesis
a surgical procedure for obtaining a sample of amniotic fluid from the amniotic sac in the uterus of a pregnant woman by inserting a hollow needle through the abdominal wall, used in diagnosing certain genetic defects or possible obstetric complications. Contemporary Examples So when Sarah was 16 weeks pregnant, she got an amniocentesis. Parents Sue […]