chorion

/kawr-ee-on, kohr-/US // ˈkɔr iˌɒn, ˈkoʊr- //UK // (ˈkɔːrɪən) //

绒毛膜,绒毛,绒毛膜炎,绒毛膜病

Definitions

n.名词 noun

1
- : Embryology. the outermost of the extraembryonic membranes of land vertebrates, contributing to the formation of the placenta in the placental mammals.
- : Zoology. the membrane around the eggs of certain insects, secreted by cells of the ovary.

The first thing that is formed is the amnios; the next the chorion; and they enwrap the seed round like a curtain.
The whole being surrounded by two membranous coverings, the outer one called the chorion, and the inner one the amnion.
Twins coming from one egg have the same chorion and can thereby be diagnosed as such.
It also sometimes brings away part of the amnios, and even the chorion, upon its head like a cap.
The surface of the chorion is covered evenly with minute villi, constituting a diffuse non-deciduate placenta.