By measuring telomeres, some scientists believe they can determine biological age, which doesn't always equal chronological age. That means some people may be biologically older or younger than their age, said Jerry Shay, professor and vice chairman of cell biology at UT Southwestern Medical Center in Dallas.
It is of ectodermal origin and is continuous with the skin at various body openings such as the eyes, ears, nose and mouth, the urethral opening and the anus. Some mucous membranes secrete mucus, a thick protective fluid. The function of the membrane is to stop pathogens and dirt from entering the body and to prevent bodily tissues from becoming dehydrated.
Examples of mucous membranes includes: lips, mouth, nasal passages, middle ear and the eustachian tube. Other mucous membranes include the lining of the digestive tract, the lining of the urogenital tract (including the urethra and vagina), the lining of the respiratory tract, and your eyes (conjunctival membranes). 1  Mucous membranes are rich with mucous glands that secrete mucus to help keep the membranes moist. The human body has 4 types of tissue with which our organs, bones, cartilage, and other parts of the body are made. One of the types, epithelium, is subdivided into two categories: mucous membranes, and serous membranes.