chorion

American  

[kawr-ee-on, kohr-] / ˈkɔr iˌɒn, ˈkoʊr- /

noun

1. Embryology. the outermost of the extraembryonic membranes of land vertebrates, contributing to the formation of the placenta in the placental mammals.

2. Zoology. the membrane around the eggs of certain insects, secreted by cells of the ovary.

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chorion British  

/ ˈkɔːrɪən /

noun

1. the outer of two membranes that form a sac around the embryonic reptile, bird, or mammal: contributes to the placenta in mammals See also amnion

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chorion Scientific  

/ kôr′ē-ŏn′ /

1. The outer membrane that encloses the embryo of a reptile, bird, or mammal. In mammals, the chorion contributes to the development of the placenta.

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Other Word Forms

• chorial
  adjective
• chorionic
  adjective
• subchorionic
  adjective

Etymology

Origin of chorion

1535–45; < New Latin < Greek chórion membrane enclosing the fetus

Example Sentences

See Examples For:

chorion

Four embryonic membranes form to support the growing embryo: the amnion, the yolk sac, the allantois, and the chorion.

From Textbooks ● Jun. 19, 2013

The development of the chorion will be discussed in more detail shortly, as it relates to the growth and development of the placenta.

From Textbooks ● Jun. 19, 2013

The mechanism of gas exchange at the chorion is similar to gas exchange at the respiratory membrane.

From Textbooks ● Jun. 19, 2013

Blood cells and vessel production in structures outside the embryo proper called the yolk sac, chorion, and connecting stalk begin about 15 to 16 days following fertilization.

From Textbooks ● Jun. 19, 2013

This latter portion, the veil that passes from the edge of the placenta, is formed of the two membranes we have mentioned, namely, the chorion and the amnion.

From The Prospective Mother, a Handbook for Women During Pregnancy by J. Morris (Josiah Morris) Slemons