currently we define saliva and salivary glands very generally in functional terms but it may be more appropriate to split this class. From WP: In most vertebrates, saliva does not contain any enzymes, consisting of mucus and water only, and its primary function is to moisten food while eating. As a result, true salivary glands are rarely found in fish or aquatic tetrapods, although there are often individual mucus-secreting cells. Amphibians have a single salivary gland, the intermaxillary gland, located in the forward part of the palate. Reptiles and birds normally have only very small glands on the lips, palate, and base of the mouth, although there are some birds with large glands, which produce a sticky saliva that helps in nest-building. The distinct parotid, submandibular, and sublingual glands are only developed in mammals.

http://upload.wikimedia.org/wikipedia/commons/5/51/Illu_quiz_hn_02.jpg

A gland that produces the saliva. [Bemis_WE, Functional_Anatomy_of_the_Vertebrates:_An_Evolutionary_Perspective, Glossary_G-25, Grande_L, Liem_KF, Third_Edition_(2001)_Orlando_Fla.:_Harcourt_College_Publishers, Walker_WF][VHOG]

uberon

glandulae salivariae

In air-feeding animals, the lack of water column to lubricate the food has been compensated for by the evolution of the salivary glands. These glands are present only in amniotes and are controlled by the parasympathetic system.[well established][VHOG]

UBERON:0001044

The salivary glands in mammals are exocrine glands, glands with ducts, that produce saliva. They also secrete amylase, an enzyme that breaks down starch into maltose. In other organisms such as insects, salivary glands are often used to produce biologically important proteins like silk or glues, and fly salivary glands contain polytene chromosomes that have been useful in genetic research. The salivary glands of some species are modified to produce enzymes; salivary amylase is found in many, but by no means all, bird and mammal species (including humans, as noted above). Furthermore, the venom glands of poisonous snakes, Gila monsters, and some shrews, are modified salivary glands

• duct of salivary gland

• salivary gland primordium

• duct of salivary gland

• salivary gland epithelium
• acinus of salivary gland
• duct of salivary gland