title: [Ultrastructure of human yolk sac].
abstract: The yolk-sac of a 15 mm and 20 mm long human embryo was investigated by the aid of electron microscope. Ultrastructure of the yolk-sac and that of the precursors of haemopoietic cells is described. The latter have been found to have a close correlation with endodermal cells.
mesh_terms: D001755:Blastocyst / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D003896:Desmosomes / Q000648:ultrastructure; D004707:Endoderm / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D004900:Erythroblasts / Q000648:ultrastructure; D005260:Female; D005333:Fetus / Q000098:blood supply; D005865:Gestational Age; D006412:Hematopoietic Stem Cells / Q000648:ultrastructure; D006801:Humans; D007044:Hysterectomy; D007889:Leiomyoma / Q000601:surgery; D008928:Mitochondria / Q000648:ultrastructure; D011247:Pregnancy; D014594:Uterine Neoplasms / Q000601:surgery; D014817:Vitelline Membrane / Q000648:ultrastructure*
vernacular_title: Az emberi sziktasak ultrastruktúrája