Amniotic Sac (Noun)
Meaning
Thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals).
Classification
Nouns denoting animals.
Examples
- The developing embryo was completely enveloped in the protective amniotic sac that filled with amniotic fluid for buoyancy and temperature regulation.
- A microscopic view of the embryo at four weeks shows the development of major organs inside the transparent walls of the amniotic sac.
- Researchers closely observed the zebra embryo developing in the womb and surrounded by a fluid-filled amniotic sac that mimicked conditions of early vertebrate life on land.
- Ultrasound revealed a viable pregnancy, showing a strong fetal heartbeat and movement of the baby safely encased within its protective amniotic sac.
- Early stages of the human fetus form while wrapped inside a fragile, protective membrane of the amniotic sac which can break, a situation called rupture of membranes, close to or at birth.