Under TEM, different kinds of secretory granules can be seen in the cytoplasm of the glandular cell bodies and in the connecting glandular tegument.

• 离腺皮层远的腺细胞体电子密度高并含有与腺皮层相应的典型分泌颗粒，而靠近腺皮层的腺细胞体电子密度低，所含分泌颗粒较少。