MeSH definition : An extra-embryonic membranous sac derived from the YOLK SAC of REPTILES; BIRDS; and
MAMMALS. It lies between two other extra-embryonic membranes, the AMNION and the CHORION.
The allantois serves to store urinary wastes and mediate exchange of gas and nutrients
for the developing embryo.;
An extra-embryonic membranous sac derived from the YOLK SAC of REPTILES; BIRDS; and
MAMMALS. It lies between two other extra-embryonic membranes, the AMNION and the CHORION.
The allantois serves to store urinary wastes and mediate exchange of gas and nutrients
for the developing embryo.