In 1909, Western Union and ADT came under the control of American Telephone & Telegraph Company (AT&T). ADT began to expand into new areas, such as fire alarms and security alarms between 1910 and 1930, but was kept separate from AT&T's Holmes alarm business. ADT became a publicly owned company in the 1960s.
It has moist membranes. Many, but not all (urinary), secrete mucous. Serous: Lines open body cavities that are closed to the exterior body surface. composed of simple squamous epithelium resting on thin layer of areolar connective tissue.
Membranes. 1  Mucous membranes line cavities that open to the outside of the body (digestive, respiratory, excretory, and reproductive tracts). 2  They contain glands and secrete mucus. 3  Serous membranes line trunk cavities that do not open to the outside of the body (pleural, pericardial, and peritoneal cavities).