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.
A virtual connective-tissue membrane covered by a single layer of mesothelial cells, which lines body cavities (e.g., pericardium, peritoneum, pleura) and covers the outer surface of organs (e.g., heart, intestines, and lungs) present in those cavities.