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.
Serous membranes are epithelial tissues that line body cavities that do not open to the exterior. These cavities include the thoracic cavity, the mediastinum (medial part of the thoracic cavity) and the abdominal cavity (superior part of the abdominopelvic cavity). Each serous membrane is basically a flattened âloopâ of membrane that is