allantoic sac
Also found in: Dictionary, Thesaurus, Encyclopedia.
al·lan·to·ic sac
the dilated distal portion of the allantois; it forms part of the placenta in many mammals.
Farlex Partner Medical Dictionary © Farlex 2012
allantoic sac
The expanded end of the allantois, well developed in birds and reptiles.
See also: sac
Medical Dictionary, © 2009 Farlex and Partners