The yolk sac (YS) is the initial embryonic structure visible on ultrasound within the gestational sac (GS), typically detectable as early as 5 weeks of gestation, corresponding to 3 weeks ...

A stem-cell derived human embryo model showing blue cells (embryo), yellow cells (yolk sac) and pink cells (placenta). Scientists have grown an entity that closely resembles an early human embryo ...

Complications from a condition known as "yolk sac retention" were the possible cause of death, the statement said. The condition, common in poultry farms, indicates the entry of bacteria through ...

Created from stem cells, without eggs, sperm, or a womb, the embryo model had a yolk sac and a proto-placenta, resembling a ...

Watch an ink injection into the yolk sac artery of a 72 hour-old chick embryo to reveal its beating heart vasculature. This was shot by Anna Franz using a reflected light microscopy technique in ...

a: Lateral view of a 4-week embryo showing the relationship of primordial gut to yolk sac. b: Drawing of median section of the embryo showing the early digestive system and its blood supply.

The egg is a capsule that contains a developing animal and a yolk sac which the young gets its nutrition from. A capsule usually houses one embryo, but in some species there are multiple embryos per ...

Several thousand cells near the base of the yolk sac become very large, migrate individually into the gut mesoderm, up the mesenteries and invade the genital ridges. These are the primitive sex cells ...