title: Ultrastructure of the atrium of the human embryonic and foetal heart.
mesh_terms: D004622:Embryo, Mammalian / Q000648:ultrastructure; D005260:Female; D005318:Fetal Heart / Q000648:ultrastructure*; D005333:Fetus / Q000648:ultrastructure; D006325:Heart Atria / Q000196:embryology; D006801:Humans; D011247:Pregnancy