noun
- Plural of amnion; the innermost membrane that surrounds and protects the embryo or fetus in mammals, birds, and reptiles.
Usage: technical/medical; biology
Examples
- The amnions of different vertebrate species show variations in thickness and structure.
- During fetal development, the amnions protect the developing baby from physical injury.
- Biologists study amnions to understand how embryos are protected in the womb.
- The amnions secrete amniotic fluid that cushions the fetus.
- Comparative anatomy examines the amnions across various animal groups.