Synonyms
spit, saliva
Classification
The term “salivary glands” (Glandulae salivatoriae) covers all those exocrine glands that produce saliva and secrete it into the oral cavity. (In the past, the pancreas was also counted among the salivary glands, a classification that has since been abandoned, which is why today, when we speak of saliva, we usually mean oral saliva. )In humans, a distinction is made between large and small salivary glands.
There are three large salivary glands, which are separate organs and have a fixed boundary: The parotid gland (Glandula parotis), the mandibular salivary gland (Glandula submandibularis) and the sublingual salivary gland (Glandula sublingualis). Together these are responsible for about 90% of the saliva produced. The remaining 10% are formed by the small salivary glands (lip glands, cheek glands, tongue glands, palatal glands, molar glands), which are scattered almost everywhere in the submucosa of the oral mucosa.
Production and secretion
There are two forms of saliva: serous saliva, which is rather thin to watery and is produced under the influence of the parasympathetic part of the autonomic nervous system, and mucous (mucinous) saliva, which is rather slimy to viscous and is produced under sympathetic influence. The parotid gland is purely serous, which means that it only releases thin saliva. The other two large salivary glands are mixed glands, whereby the mandibular salivary gland is sero-mucosal, i.e. it consists mainly of areas that secrete serous saliva, whereas the sublingual salivary gland is called mucose-serous because it has more end pieces that produce mucosal saliva. All the excretory ducts of the large salivary glands ultimately lead into the oral cavity (the sublingual and mandibular salivary glands have a common excretory duct, the end of which is located under the tongue; the excretory duct of the parotid gland leads into the mucous membrane opposite the first upper molar), which is why a mixture of the different types of saliva can be found there. By producing saliva, the salivary glands perform important functions in digestion, defence and dental hygiene.
