human_reference_atlas part of Homo sapiens heart atrioventricular node http://upload.wikimedia.org/wikipedia/commons/5/50/ConductionsystemoftheheartwithouttheHeart.png http://upload.wikimedia.org/wikipedia/commons/9/92/Gray501.png A-V node MAT:0000498 TAO:0005070 Three major adaptations, or 'novel cardiac components', that were not present in the ancestor chordate heart tube can be distinguished in the lower vertebrate heart: the atrium, ventricle, and possibly the muscular sinus venosus. Furthermore, within the ventricular component a compact outer myocardial component and an interiorly localized extensive trabecular component can be distinguished. The specific activation of the ventricle adds to its complexity as follows. The depolarizing impulse travels rapidly from the atrioventricular node toward the apex and then toward the conal region, achieving activation from apex to base.[uncertain][VHOG] NCIT:C32161 BTO:0005689 nodus atrioventricularis atrioventricular node EMAPA:35153 MESH:D001283 FMA:9478 EHDAA2:0004183 Aschoff-Tawara node uberon atriovetricular node MA:0000095 Wikipedia:Atrioventricular_node downstream pacemaker nodus atrioventricularis atrioventricular node UMLS:C0004247 An area of conducting tissue between the atria and the ventricles of the heart that conducts the normal electrical impulse from the atria to the ventricles. VHOG:0001474 SCTID:277688002 AV node ZFA:0005070 node of Tawara AS AV nodal muscle tissue UBERON:0002352 atrioventricular nodal muscle tissue atrio-ventricular node EFO:0000276 GAID:558 conducting tissue of heart atrioventricular region