Search Ontology:
Cell Ontology

yolk sac

Term ID
UBERON:0001040
Synonyms
  • saccus vitellinus
  • vesicula umbilicalis
Definition
A sac-like expansion of the ventral wall of the intestine, narrowed into a yolk stalk near the body[Hyman's]. Membranous sac attached to an embryo, providing early nourishment in the form of yolk in bony fishes, sharks, reptiles, birds, and primitive mammals. It functions as the developmental circulatory system of the human embryo, before internal circulation begins. In the mouse, the yolk sac is the first site of blood formation, generating primitive macrophages and erythrocytes[WP]. http://en.wikipedia.org/wiki/Yolk_sac
References
Ontology
Cell Ontology
Relationships
has parts
is a type of
has subtype