Parotid gland. Light micrograph of a section through a normal human parotid gland. The parotid is one of the salivary glands. It consists of small sacs (acini) arranged in lobes (blocs of blue-staining cells); the clear spaces represent the connective tissue between lobes. The masses of secretory cells (blue) produce a watery (serous) secretion (stained brown), which is seen here concentrated in ducts (stained brown) within the lobes. Saliva helps to keep the mouth moist and healthy, and contains enzymes that begin the process of digestion. Magnification: x160 at 35mm size.