房室束细胞比移行细胞大、核染色质多、肌丝和肌原纤维及其分支也多、闰盘发达完整。
The cells in the HB were larger than the transitional cells , with abundant chromatin in the nuclei , more myofibers and myofibrils and branches . The intercalated disks were well developed .
染色质丝