- yolk membrane
- vitelline m.
Medical dictionary. 2011.
yolk membrane
Look at other dictionaries:
yolk sac — n. Zool. 1. a saclike vascular membrane containing yolk, an outgrowth from the ventral surface of very yolky vertebrate embryos, as those of fishes, birds, or reptiles, that supplies nourishment to the embryo 2. a homologous organ in most… … English World dictionary
yolk sac — yolk′ sac n. dvl an extraembryonic membrane that encloses the yolk of eggs • Etymology: 1860–65 … From formal English to slang
Yolk sac — Not all yolk has to do with birds’ eggs. Human embryos have a yolk sac, a membrane outside the embryo but connected by a tube (the yolk stalk) though the umbilical opening to the embryo’s midgut. The yolk sac serves as an early site for … Medical dictionary
Yolk sac — Infobox Embryology Name = Yolk sac Latin = GraySubject = 11 GrayPage = 54 Caption = Human embryo of 2.6 mm. Caption2 = Human embryo from thirty one to thirty four days System = CarnegieStage = 5b Days = 9 Precursor = endoderm GivesRiseTo =… … Wikipedia
yolk sac — noun 1. membranous structure that functions as the circulatory system in mammalian embryos until the heart becomes functional • Syn: ↑vitelline sac, ↑umbilical vesicle, ↑vesicula umbilicus • Hypernyms: ↑sac 2. membranous structure enclosing the… … Useful english dictionary
membrane — 1. A thin sheet or layer of pliable tissue, serving as a covering or envelope of a part, as the lining of a cavity, as a partition or septum, or to connect two structures. SYN: membrana [TA]. 2. SYN: biomembrane. [L. membrana, a skin or m … Medical dictionary
yolk sac — Embryol. 1. an extraembryonic membrane that encloses the yolk of eggs in birds, reptiles, and marsupials and that circulates nourishment from the yolk to the developing embryo. 2. a similar membrane in placental mammals that encloses a mostly… … Universalium
yolk granule — a membrane bounded sac containing yolk. These 50 μm granules are densely packed in the interior of the yolk cell and make up most of the cell … Dictionary of ichthyology
yolk sac — thin membrane which surrounds the yolk of an egg and supplies nutrients to the embryo (in mammals, the yolk sac ceases to function when the placenta forms) … English contemporary dictionary
yolk — /joʊk / (say yohk) noun 1. the yellow and principal substance of an egg, as distinguished from the white. 2. Biology that part of the contents of the egg of an animal which enters directly into the formation of the embryo (formative yolk or… …
