What You Have To Know About Saliva

Saliva can be a pretty uncommon subject. I mean really, which one of us has ever stopped and thought about what happens inside our mouths? Most of us say things like, "that makes my mouth water" without ever thinking about it. Well today, we are going to stop and think. We are going to take a good long look at that watery substance we call saliva.

How And Where Is It Produced?

Saliva is produced in your mouth, it is not produced anywhere else and it is not similar to any other liquid in human body. Sweat is something altogether different, urine is not even close. Saliva has its own unique composition and functions.

Yet, before we explore that, let's talk for a minute about how saliva is produced. Since it occurs in our mouths, it only makes sense that it would be produced there right? However, it's not like our mouths just create it out of nowhere. Saliva is produced in salivary glands located within our mouths through stimulation of either sympathetic or parasympathetic nervous system. This gives two different kinds of saliva. Sympathetic stimulation releases norepinephrine and produces saliva that facilitates respiration, while parasympathetic stimulation releases acetylcholine which creates saliva that facilitates digestion.

Salivary glands contain small groupings of cells, their technical name is acini or salivary acinar cells, which being stimulated by nervous system create the basis for saliva production. Before it enters your mouth from the salivary duct, it is filled with different substances and compounds like enzymes and proteins that help digestion and perform other useful functions.

Salivary gland does not control production volume - that is all handled by the nervous system. Depending on the quantity and composition of your food as well as condition of the body, your nervous system decides how much saliva to produce at any given time.

Saliva Composition

As you can expect, saliva is mostly composed of water - its actual proportion is approximately 99.5%. So what about that other 0.5%? Well that part contains a lot of important chemical substances such as mucous, different enzymes, electrolytes, antibacterial compounds and a few glycoproteins. Yet that 0.5% is pretty important when it comes to the functions of saliva for the human body.

Functions

Saliva is very important substance which has number of functions, there are only main of them:

1. Digestive
   Chemical substances in saliva break down your food when you are chewing, while water helps to dilute food to a degree making it particles smaller and easier for stomach acid to surround them and begin to digest. Not the most exciting subject, I know. Yet, it is pretty amazing to think about how much goes into digesting your food before it ever hits the stomach. From your nervous system to enzymes and electrolytes, saliva is a great contributor to your overall digestive health.
   
2. Lubricative
   Dry food and even rubbing during speaking can seriously damage throat, so saliva lubricates it, thereby protecting from mechanical injuries.
   
3. Antimicrobial
   Saliva has both specific and non-specific immunologic effect, so not only washes out the mouth, but disinfects it also, thus controlling microorganisms inside it and preventing infections.
   
4. Tasting
   Saliva includes hormones, which are important for developing taste receptor cells.
   
5. Ionisation
   Saliva also includes number of various ions, which help to prevent formation of salts in the mouth, thereby keeping normal acidity in it and protecting minerals in dental enamel from dissolving.

In animal world saliva also has such a specific functions like wound licking and glueing of the bird nests.