1. Membranous structure that functions as the circulatory system in mammalian embryos until the heart becomes functional
   - yolk sac, umbilical vesicle, vesicula umbilicus

Derived forms: vitelline sacs

Type of: sac

• glazier
• gleam
• gleaming
• glean
• gleaner
• gleba
• glebe
• glebe house
• Glechoma
• Glechoma hederaceae
• Gleditsia
• Gleditsia aquatica
• Gleditsia triacanthos
• glee
• glee club
• gleeful
• gleefully
• gleefulness
• gleet
• Gleichenia
• Gleichenia flabellata
• Gleicheniaceae
• glen
• Glen Canyon Dam
• Glen Gebhard