Noun: amniotic sac ,am-nee'ó-tik sak
- Thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)
"The amniotic sac provides a protective fluid environment for the developing foetus";
- amnion, amnios
Derived forms: amniotic sacs
Type of: sac
Part of: amniote, fetal membrane
Encyclopedia: Amniotic sac