Classification ◆ Covering epithelium(被覆上皮): cover body surface or line the inner surface of body cavities tubes and sac ◆ Glandular epithelium(腺上皮): the epithelium which main function is secretion ◆ Sensory epithelium(感觉上皮): the epithelium which has special sensory function.3 Classification ◆ Covering epithelium(被覆上皮): cover body surface or line the inner surface of body cavities, tubes and sac. ◆ Glandular epithelium(腺上皮): the epithelium which main function is secretion. ◆ Sensory epithelium(感觉上皮): the epithelium which has special sensory function