Conclusion
We conclude that the RN connects with the AVN, which suggests direct
electrical conduction between them. The entrance of the atria into the
AVN is the distal part of the RN. The fast pathway of the AVN is
strongly suggested by the structure of the RN and its extension. The
level of the start of the CN is a more complex region than previously
described. First, it stretches downward, forming the transitional area
between the His bundle and AVN; second, it extends backward, forming the
main body of the CN; and third, it accepts the insertion of the end of
the RN.