10 surprising facts about human saliva
Although most people look at saliva as something disgusting, it plays an important role in our lives. Thanks to it we chew, swallow and digest the food. It fights bacteria in the mouth and prevents the appearance of caries. We present 10 curious facts that will make you change your mind about saliva.
Saliva is just water - the saliva consists of about 99% water. The other 1% is electrolytes and organic substances, including digestive enzymes and small amounts of uric acid, cholesterol and mucins (the proteins that form mucus).
There is a medical standard for saliva - healthy people emit between 2 to 6 glasses of saliva without counting activities like eating or chewing that open the salivary glands.
Salivation takes place at a circadian rhythm - our body usually produces the most saliva in the late afternoon, and at least at night. Saliva separation is controlled by the vegetative nervous system (similar to heart rhythm), which means it is an unconscious process.
Saliva fights bacteria in the mouth - we are not saying "lick the wounds". The saliva is full of white blood cells that fight infections. In the study, white blood cells are more effective in destroying bacteria if they come from saliva.
Prevent caries - calcium, fluoride and phosphate in saliva strengthen teeth. Saliva also cleans food particles and neutralizes plaque. Chewing chewing gum increases the saliva, thus protecting the teeth.
You need saliva to taste anything - saliva acts as a solvent of flavors that transports the dissolved food to the taste buds. It also keeps these receptors healthy by preventing them from drying out and from bacterial infections. People who have dry mouth (xerostomia) have a dull taste. Because many drugs cause dry mouth as a side effect, scientists have developed artificial sprays to "create" saliva.
With the saliva, millions of bacteria are exchanged - about 80 million bacteria are exchanged during a 10-second kiss.
People are not born with saliva - babies are starting to saliva when they are two to four months old. Unfortunately, they develop control over the muscles of their mouths later when they are two years old. For this purpose, the pacifiers are invented.
Stress can reduce the amount of saliva in the mouth - our body is set to provide us with the energy needed to overcome very tense situations. Blood rises, the heart accelerates its rhythm, and the lungs take up more oxygen. Since the moment is obviously inappropriate for fast food, the digestive system slows down its action, including saliva.
The absence of saliva is considered a sign of guilt - in some ancient societies saliva was used as the main lie detector. In ancient India, accused of a lie were forced to chew a grain of rice. If they had told the truth, they had to have enough saliva to spit out the grains. If one of them was lying, his mouth was dry and the rice stuck in their throats.
Source: www.sciencealert.com ,https://www.gettyimages.com