title: Cholinesterase and the atrioventricular node and bundle in the human fetus up to midterm.
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis*; D002802:Cholinesterases / Q000032:analysis*; D005260:Female; D005333:Fetus / Q000166:cytology / Q000201:enzymology*; D006329:Heart Conduction System / Q000166:cytology / Q000201:enzymology*; D006651:Histocytochemistry; D006801:Humans; D011247:Pregnancy; D013194:Staining and Labeling; D013997:Time Factors
chemical_list: D000110:Acetylcholinesterase; D002802:Cholinesterases