[A morphometric analysis of the structure of the atrioventricular node of the sheep heart]

The work deals with the geometry of the structure of different sections of the atrio-venticular (A-V) node of the sheep's heart and measurement of the diameter of fibres in its three zones: atrio-nodal (A-N), the node proper (N) and transition of the node into His bundle (NH). The revealed difference in the diameter of contacting fibres of N and NH areas under worse conditions of conducting may contribute to block of excitation. The geometrical features of A-N and N areas contribute to prolonged delay of excitation and geometrical parameters of the site of contact between N and NH zones to its block.