loading...| Preferred Name |
yolk sac |
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| Synonyms |
vesicula umbilicalis saccus vitellinus |
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| Definitions |
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]. |
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| ID |
http://purl.obolibrary.org/obo/UBERON_0001040 |
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| database_cross_reference |
EHDAA2:0002212 MESH:D015017 SCTID:362845002 CALOHA:TS-1130 VHOG:0000830 EFO:0003078 Wikipedia:Yolk_sac BTO:0001471 UMLS:C0043425 NCIT:C14128 EMAPA:16085 EHDAA:164 FMA:87180 GAID:1301 |
|
| 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]. |
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| depiction |
http://upload.wikimedia.org/wikipedia/commons/1/17/Gray22.png |
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| editor note |
consider splitting class |
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| external_definition |
One of the extraembryonic fetal membranes that balloons out from the fetal midgut. [TFD][VHOG] the extraembryonic tissue membrane, formed from the visceral endoderm and the extraembryonic mesoderm, which is located ventral to the embryonic disc and is connected to the presumptive midgut of the embryo; the yolk that it contains is the site of embryonic hematopoiesis and vitelline circulation is involved in early embryonic circulation; it is the origin of the primordial germ cells |
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| has_obo_namespace |
uberon |
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| has_related_synonym |
vesicula umbilicalis saccus vitellinus |
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| homology_notes |
Structures homologous to the four extraembryonic membranes of reptiles and birds appear in mammals: amnion, chorion, yolk sac, and allantois.[well established][VHOG] |
|
| id |
UBERON:0001040 |
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| in_subset |
http://purl.obolibrary.org/obo/uberon/core#efo_slim |
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| label |
yolk sac |
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| notation |
UBERON:0001040 |
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| prefLabel |
yolk sac |
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| taxon_notes |
In therians, a structure homologous to the yolk sac is is present, but contains no yolk platelets. Instead it is filled with fluid [ISBN:0073040584 (Vertebrates, Kardong)] |
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| subClassOf |
http://purl.obolibrary.org/obo/UBERON_0005292 |