egg membrane


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egg mem·brane

, secondary egg membranetertiary egg membrane
the investing envelope of the oocyte; a primary egg membrane is produced from ovarian cytoplasm (for example, a vitelline membrane); a secondary egg membrane is the product of the ovarian follicle (for example, the zona pellucida); a tertiary egg membrane is secreted by the lining of the uterine tube (for example, a shell).

egg mem·brane

, secondary egg membrane , tertiary egg membrane (eg mem'brān, sekŏn-dar-ē, tĕrshē-ăr-ē)
A primary egg membrane is produced from ovarian cytoplasm (e.g., a vitelline membrane); a secondary egg membrane is the product of the ovarian follicle (e.g., the zona pellucida); a tertiary egg membrane is secreted by the lining of the oviduct (e.g., a shell).

egg membrane

Any of the protective membranes or envelopes enclosing an ovum. It may be primary (formed by egg itself, as in vitelline membrane), secondary (formed by follicle cells, as in zona pellucida), or tertiary (formed by oviduct or uterus, as in albumin and shell of hen's egg).
See also: membrane

egg membrane

any membrane, shell or jelly-like layer surrounding and protecting the EGG, including primary membranes secreted by the OVUM or OOCYTE, secondary membranes secreted by cells of the ovary and tertiary membranes, for example albumen and egg shell, secreted by glands of the oviduct.
References in periodicals archive ?
Because of the more rapid development and shorter duration time, the presence of stage I embryos, which are enveloped in an egg membrane, was less often observed.
As cuttlefish develop, the outer egg membrane turns clear enough for the embryos to peek out at the big world around them.
Biova LLC, Johnston, IA, a supplier of water-soluble egg membrane, has finalized an agreement with Maypro Industries, Purchase, NY, which will be the preferred distributor of Biova's ingredient portfolio in Japan and Taiwan.
that the extra egg membrane is absent from the central part of the upper egg surface and that this acts as a fertilization pore, through which the spermatozoid penetrates the egg (Cao et al.