Saliva is a watery substance secreted by the salivary glands which are part of the upper digestive system. The salivary glands are exocrine glands, that is, they secrete substances outside the body or within a body cavity, in this case the oral cavity.
The function of the salivary glands is simply to produce and discharge saliva in the oral cavity. The salivary glands secrete between 1 to 1.5 liters of saliva in a 24 hour period.
Over 99% of saliva is water and the remaining 1% is made of proteins, electrolytes, enzymes, amino acids and other substances essential for good oral health, chewing, and food digestion.
Some of the Functions Of Salivary Glands:
- Dilution of sugars after eating food and having drinks
- Degradation of bacterial cell walls inside the mouth and performing a cleansing of the mouth
- Maintaining the pH of the mouth by controlling the acid production
- Repair of the broken tissue inside the mouth
- The presence of calcium and phosphates in the saliva help in remineralization of the enamel as well
- Helps in chewing and swallowing of the food by making it softer
- Breaks down the food with enzymes and turns it into simpler sugars
- Keeps the oral tissues lubricated and facilitates speech
How do they work?
Parotid glands are the largest of the major salivary glands. Each of these glands measures 6 cm long and 3-4 cm wide and can weigh up to 30 grams.Approximately 20% of saliva is produced by parotid glands. This saliva is serous, that is, more liquid and fluid.
These little glands are the size of a walnut and are located beneath the lower jaw, on the back of the floor of the mouth (outside of the oral cavity).
Despite their small size, approximately 65-70% of saliva entering the oral cavity comes from these glands. Saliva secreted by the submandibular glands is more viscous than that secreted by the parotid, but it is still quite fluid.
Sublingual glands are the smallest of the major salivary glands. They are located on the floor of the mouth under the tongue. Approximately 5% of the saliva comes from these glands. This saliva is predominantly mucous, has a viscous texture, and flows into the mouth through the sublingual ducts.
Sometimes, sialoliths (stones) form in the salivary gland ducts, blocking the flow of saliva, and causing pain and swelling in the affected gland. Salivary stones most often affect the submandibular glands but may also affect the parotid.
Why are salivary glands important?
Saliva is crucial to maintaining the health of the mouth as it not only helps in the breakage of food particles, but also maintains the pH balance of the mouth. Salivary glands also facilitate the speech function. The lack of saliva can result in xerostomis, a condition that can increase the decay of teeth, and cause bad breath. The digestive system also suffers as the food particles cannot be broken down. This could also increase the amount of acid in the mouth, as the saliva won’t be present to balance it out.
The salivary glands make use of tiny ducts to produce saliva. Thus, if they are inflamed or blocked, the production of saliva will suffer, resulting in the dry mouth condition. Your dentist can thus, prescribe you medicines to curb this condition.