<unk> s secrete<unk>  fluid. They contain<unk>  acini, a grouping of<unk>  cells that secrete<unk>  fluid, isotonic with blood plasma, that contains enzymes such as alpha-amylase.<unk> s are most common in the parotid<unk>  and lacrimal<unk>  but are also present in the submandibular<unk>  and, to a far lesser extent, the sublingual<unk> .
Serous gland
Callus
Ovary
Areolar gland
Skene's gland
Meibomian gland
Lutetium 
Adrenal gland