|—n , pl -nions, -nia|
|See also chorion the innermost of two membranes enclosing an embryonic reptile, bird, or mammal|
|[C17: via New Latin from Greek: a little lamb, from amnos a 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.
|amnion (ām'nē-ən) Pronunciation Key
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.