Clinical Engineering departments will sometimes hire not just biomedical engineers, but also industrial/systems engineers to help address operations research/optimization, human factors, cost analysis, etc. Also see safety engineering for a discussion of the procedures used to design safe systems.
The 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. The parotid gland makes 25% of the saliva and drains into the mouth near the upper teeth. The submandibular gland makes 70% of the salvia and drains into the mouth from under the tongue. The sublingual gland makes 5% of the saliva and drains into the floor of the mouth.
The first type of glands are called intrinsic salivary glands. These are small glands dispersed throughout the mouth. They have openings in different parts of the mouth, such as under the base of the tongue, on the inside of the lips, and on the inside of the cheeks.