Wikipedia
Serous gland
Serous glands contain serous acini, a grouping of serous cells that secrete serous fluid, isotonic with blood plasma, that contains enzymes such as alpha-amylase.
Serous glands are most common in the parotid gland and lacrimal gland but are also present in the submandibular gland and, to a far lesser extent, the sublingual gland.