Tags: Anatomical Structure.
The mucous membranes (or mucosae or mucosas; singular mucosa) are linings of mostly endodermal origin covered in epithelium which are involved in absorption and secretion. They line cavities that are exposed to the external environment and internal organs. They are at several places contiguous with skin: at the nostrils the lips of the mouth the eyelids the ears the genital area and the anus.