The outer membrane which invests the fetus in the womb; also, the similar membrane investing many ova at certain stages of development.
The outer membrane of seeds of plants.
the wall of the chorionic cavity, consisting of ectoblast (trophoblast) and mesoblast (extra-embryonic mesoderm). Later forms two types, viz. smooth chorion (chorion laevae) and bushy chorion (chorion frondosum).
Another name for the egg shell.
The outermost extraembryonic membrane of reptiles, birds, and mammals. In eutherian mammals the chorion contributes to the formation of the placenta.
the outermost fetal membrane; becomes the principle embryonic portion of the placenta; serves a protective and nutritive function
the outer membrane surrounding the fetus
The chorion develops into the placenta. Chorionic cells have the same genetic composition as cells of the fetus. Cells of the chorion are sampled during a prenatal diagnostic test called CVS (chorionic villus sampling).
The outermost of the two membranes surrounding the gestational sac that encloses the developing embryo. Separate from the amnion until about 14 weeks of pregnancy, after which the two membranes stick together without intervening fluid. Like the placenta, with which at the margins it is joined seamlessly, derived from trophectoderm. See also: amnion See also: chorionic villus
extraembryonic membrane generated from trophoblast and extraembryonic mesoderm that forms placenta.
the outermost of the two membranes that completely envelop a fetus.
An extraembryonic membrane, consisting of the trophoblast and underlying mesoderm, that forms the placenta.
The outermost of the two fetal membranes that gives rise to the placenta.
The fetal membrane closest to the intrauterine wall that gives rise to the placenta and continues as the outer membrane surrounding the amnion.
The outermost of the two membranes surrounding the embryo/ fetus, part of which forms the fetal portion of the placenta.
outer membrane of an egg; shell
outermost membranous sac enclosing the embryo in higher vertebrates (reptiles, birds and mammals)
KOR-ee-on A membrane that develops into the placenta. 218
outermost membrane enclosing the fetus.
The two-layered structure formed from the trophoblast after implantation; secretes human chorionic gonadotropin.
one of the membranes that encloses the fetus within the uterus.
The cellular, outermost extraembryonic membrane, composed of trophoblast lined with mesoderm. It develops villi about two weeks after fertilization. Villi are the threadlike projections growing in tufts on the external surface of the chorion. At three weeks, it is vascularized by allantoic vessels.
the outer "shell" of the conceptus. Originally a sphere, out-pouching of the chorion form the primitive chorionic villi (the fetal part of the placenta)
A thick and durable substance which surrounds and encloses the eggs of all species within the order Lepidoptera. With some eggs this substance is smooth whereas with others it is decorated with symmetrical art-like features. This substance is often the first food that the newly emerged larva will have before beginning to eat its host plant.
The outermost extraembryonic membrane composed of the trophoblast. It develops into the placenta and remains as the outer of the two layers containing the amniotic fluid and the fetus.
A membrane surrounding both the yolk sac and the amnion.
The sac of tissue that encloses the amniotic sac of the fetus.
A membrane that surrounds both the yolk sac and the amnion; it has no apparent initial function but later fuses with the allantois to form the chorio- allantois membrane.
The outer membrane enclosing the embryo in reptiles, birds, and mammals. In placental mammals it contributes to the development of the placenta.
The outer casing of an egg.
Outer membrane surrounding the fetus inside of which is the amnion, amniotic fluid and developing fetus.
Layer of cells covering a fertilized ovum some of which, the chorion frondosum, will later form the placenta.
outermost membrane surrounding the egg.
The outermost layer of the foetus, which develops villi in order to facilitate foetal-maternal blood exchange, and becomes part of the placenta.
Outer membraneous tissue enveloping the developing placenta.
outer layer of the membrane
The chorion is the hard, protective, outer part of an insect egg.
The chorion surrounds the embryo and other membranes. It consists of two layers: an outer formed by the primitive ectoderm or trophoblast, and an inner by the somatic mesoderm; with this latter the amnion is in contact.