it was found that the ache-positive nerve fascicles in these regions partly contain sympathetic nerve fibres , that sympathetic nerve fibres occur in the proximity of some of the ganglionic cells that occur outside the av node/av bundle , that the arteries supplying av bundle tissue as well as av nodal tissue have perivascular plexuses of sympathetic nerve fibres , and that there is a substantial number of sympathetic nerve fibres outside purkinje fibre bundle surfaces .
C0006382
av bundle
C0034144
fibres