What is allantoim?

Allantois is a sac-like structure found in the developing embryos of mammals, reptiles, and some birds. It is formed during embryonic development from the primitive gut and serves as a repository for nitrogenous waste products. The allantois is connected to the hindgut and yolk sac and forms part of the umbilical cord, which connects the embryo to the placenta. In mammals, the allantois contributes to the formation of the urinary bladder. The allantois also plays a role in gas exchange and respiration, and in some animals, it can also store calcium and other minerals. In some species, such as birds, the allantois may also play a role in producing calcium for eggshell formation. In humans, the allantois is an embryonic structure that is typically absorbed during fetal development and does not have any known function after birth.