title: Development of atrioventricular specialized tissue in human heart.
mesh_terms: D002395:Catecholamines / Q000032:analysis; D002802:Cholinesterases / Q000032:analysis; D005333:Fetus; D006329:Heart Conduction System / Q000032:analysis / Q000196:embryology* / Q000201:enzymology; D006651:Histocytochemistry; D006652:Histological Techniques; D006801:Humans; D010232:Paraffin
chemical_list: D002395:Catecholamines; D010232:Paraffin; D002802:Cholinesterases