Yolk Sac
nounverified·updated May 18, 2026
membranous structure that functions as the circulatory system in mammalian embryos until the heart becomes functional
Framework senses
- §1
- membranous structure enclosing the yolk of eggs in birds, reptiles, marsupials, and some fishes
- §2
- membranous structure that functions as the circulatory system in mammalian embryos until the heart becomes functional
- §1 · legacy_primary
- membranous structure that functions as the circulatory system in mammalian embryos until the heart becomes functionalDR-088 backfill from the noun definition column