Sialolithiasis (sigh a lo THIGH a sis) is a condition where tiny salivary stones form in the glands. The stones, called sialoliths, are made of calcium. Some stones do not cause any symptoms, but some stones block the ducts. The saliva flow is partially or completely stopped.he three major salivary glands are the parotid gland, submandibular gland (also called the submaxillary gland), and sublingual glands. Saliva drains into the mouth through small tubes called ducts.
NASA facilities. NASA facilities exist across the United States, but also across the world. NASA Headquarters in Washington, DC provides overall guidance and political leadership to the agency. There are 10 NASA field centers, which provide leadership for and execution of NASA's work.
Print. NASA stands for the National Aeronautics and Space Administration. It is a government agency that was created by Congress in 1958. NASAâs mission is to explore space and aeronautics, or flight research. NASA is also responsible for making sure that the United States space program is conducted for peaceful purposes that can help mankind. The head of NASA has to be approved by the government.