Crossword clues for yolk sac
yolk sac
Wiktionary
n. (context anatomy English) A membranous sac attached to an embryo, providing early nourishment in the form of yolk in bony fishes, sharks, reptiles, birds, and primitive mammals.
WordNet
n. membranous structure that functions as the circulatory system in mammal embryos until the heart becomes functional [syn: vitelline sac, umbilical vesicle, vesicula umbilicus]
membranous structure enclosing the yolk of eggs in birds reptiles marsupials and some fishes; circulates nutrients to the developing embryo
Wikipedia
The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast adjacent to the embryonic disk. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though yolk sac is far more widely used. The yolk sac is important in early embryonic blood supply, and is incorporated into the primordial gut during the fourth week of development.
Usage examples of "yolk sac".
Day-old chicks don't actually need to eat (they still have plenty of reserve food in a yolk sac, which they won't use up for the next day or so), but they do like to practise pecking and play with the crumbs.
The baby would be fine for a bit without food, and so would Menet-ka, even though the latter didn't have a yolk sac to absorb.