Why do we produce saliva constantly just to swallow it back?!
Question:
Why do we produce saliva constantly just to swallow it back?
saliva magically appears inside your mouth and then when you swallow it more saliva appears like on a never ending cycle.
Answers:
The salivary glands make three different varieties of spit (which is, on average, nearly 98 percent water). The parotid glands just in front of the ears secrete an especially watery spit. The sublingual glands, under the tongue, make a more mucous-rich spit. And the submandibular (or submaxillary) glands, located under the mouth's floor and toward the rear, produce a watery-mucous-y mix.
About 70 percent of the saliva in our mouth comes from the submandibular glands.
What's the point of spit? Saliva lubricates the food we eat, making it slippery enough to swallow. Enzymes in saliva kick off the digestion of starch, turning some of it into maltose, a sugar. Saliva wets dry food, allowing us to taste it. It washes over the mouth and teeth, helpfully clearing away food particles.
When we feel queasy, the brain signals the salivary glands to step up production, making a mouthful of spit. When we finally vomit, the extra saliva protects the delicate tissues of the mouth and the vulnerable enamel on our teeth from the acidic, corrosive stomach juices.
Saliva also contains proteins that fight viruses and inhibit the growth of bacteria and funguses. Other proteins in spit speed wound healing. Saliva also contains calcium and phosphorus, key building blocks of teeth. Too little saliva means more gum disease and tooth decay.
Because saliva is synthesized by the body from blood serum, it also contains hormones, as well as markers for many diseases, from breast and oral cancer to autoimmune conditions. Scientists say that analyzing a sample of saliva may eventually become a convenient, non-invasive way to test for such diseases.
Meanwhile, scientists are also studying the complex spit of insects, like mosquitoes and ticks, that feast on blood. Tick spit, for example, contains a chemical that widens its victim's blood vessels, increasing the flow of blood under the surface of the skin. The saliva also contains at least two anti-clotting agents, to keep blood from coagulating. There are also several enzymes that function as painkillers, so we remain unaware that we're being pierced by a sharp stylet.
Tick spit lets the tiny bloodsucker perform painless surgery and feed for hours, unnoticed. By analyzing the saliva of ticks and mosquitoes, scientists have discovered up to 40 distinct chemical compounds that may have helped tiny blood-suckers to flourish. But so far, no one knows what most of the chemicals do.
Human saliva also contains many unknown substances. Last year, scientists announced they'd discovered a natural pain blocker in spit six times as powerful as morphine. They named the chemical "opiorphin," since it seems to work by prolonging the action of the body's own natural opiates. Opiorphin, they say, may also function as a natural antidepressant.