Saliva
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- For the band, see Saliva (band).
In animals, saliva is produced in and secreted from the salivary glands. It is a fluid containing:
- water
- electrolytes
- mucus Mucus in saliva mainly consists of of mucopolysaccharides and glycoproteins.
- and various enzymes. The major enzymes found in human saliva are alpha-amylase, lysozome, and lingual lipase. Amylase starts the digestion of starch and lipase fat before the food is even swallowed. It has a pH optima of 7.4. Lingual lipase has a pH optima ~4.0 so it is not activated till entering an acidic environment. Lysozome acts to lyse bacteria.
A common belief is that saliva contained in the mouth has natural disinfectants, which leads people to believe it is beneficial to "lick their wounds". Researchers at the University of Florida at Gainesville have discovered a protein called Nerve Growth Factor (NGF) in the saliva of mice. Wounds doused with NGF healed twice as fast as untreated, unlicked wounds. So in a few species, at least, saliva does have some curative powers. NGF has not been found in human saliva, but researchers do note that human spit contains such antibacterial agents as secretory IgA, lactoferrin, and lactoperoxidase. It has however not yet been shown that licking your wounds actually disinfects them.
Saliva is also known as spit. To spit or the action of spitting is also to expel saliva or other substances from the mouth. A verb for this action is to expectorate.
See also
es:Saliva fr:Salive it:Saliva lt:Seilės zh-min-nan:Chhùi-nōa nl:Speeksel pl:Ślina sv:Saliv zh:唾液