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.
Mucous membranes, also called mucosa, line the inside of cavities that open directly to the exterior environment. Mucous membranes line the gastrointestinal tract, respiratory tract, reproductive tracts and the urinary tract.This type of membrane is composed of an epithelial cell layer and an underlying connective tissue layer.The epithelial layer is an important defense mechanism that prevents the entry of pathogens and microbes into the body. The cells are tightly packed together, so fluid cannot leak through the epithelial layer.his type of membrane is composed of an epithelial cell layer and an underlying connective tissue layer. The epithelial layer is an important defense mechanism that prevents the entry of pathogens and microbes into the body. The cells are tightly packed together, so fluid cannot leak through the epithelial layer.