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.
At the tissue level, membranes form a barrier or interface (basement membranes that separate epithelia from connective tissues). On another level, epithelia and connective tissues combine to form membranes that cover and protect other structures and tissues.Types of membranes:1  Mucous membranes line cavities that connect with the exterior, including the digestive, respiratory, reproductive, and urinary tracts.n another level, epithelia and connective tissues combine to form membranes that cover and protect other structures and tissues. Types of membranes: 1  Mucous membranes line cavities that connect with the exterior, including the digestive, respiratory, reproductive, and urinary tracts.