Internodal pathways 窦房结：P细胞及过渡细胞 Sinus node 房室结：房结区，结区，结希区 A-V node -一A-V bundle,房室束 -Left bundle branch 左束支 一 Right bundle branch 右束支 Figure 9-I The sinus node and the Purkinje system of the heart, showing also the A-V node,the A-V bundle,the atrial inter- nodal pathways,and the ventricular bundle branches.窦房结:P细胞及过渡细胞 房室结:房结区,结区,结希区 房室束 左束支 右束支