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. The sticky, thick fluid secreted by some mucous membranes and glands is termed mucus.
The glans clitoridis and the clitoral hood, as well as the glans penis (the head of the penis) and the inner layer of the foreskin, are all mucous membranes. The urethra is also a mucous membrane. The secreted mucus traps the pathogens in the body, preventing any further activities of diseases.
Some examples of mucosae