Critical to maintaining oral and dental health.
A complex fluid made up of secretions from salivary glands and gingival crevicular fluid.
Saliva moistens and softens food, and along with the chewing action of the teeth, transforms the food into a smooth bolus.
The bolus is further helped by the lubrication provided by the saliva in its passage from the mouth into the esophagus.
Ninety percent produced by the major salivary glands the parotid, submandibular and sublingual glands.
Approximately 10% produced by minor salivary glands in the oral mucosa and include lingual, labial, buccal, palatine and glossopalatine areas.
Saliva-resting secretion if primarily from the submandibular glands.
Unstimulated flow 0.3 mL/min.
Flow during sleep decreases by 50%.
The normal pH range of saliva is between 6 and 7.
Salivary glands produce 1-1.5 L of saliva per day.
About 45% of saliva is produced by the parotid gland, 45% by the submandibular glands, and 5% each by the sublingual and minor salivary glands.
Saliva is produced at a low basal rate throughout the day.
During meals saliva production increases 10-fold increase in flow during meals.
Functions to maintain lubrication of the mucous membranes and to clear food, cellular debris, and bacteria from the oral cavity.
Contains salivary amylase, which assists in initial digestion of food.
In saliva are the digestive enzymes amylase and lipase.
Amylase starts to work on the starch in carbohydrates, breaking it down into the simple sugars of maltose and dextrose that can be further broken down in the small intestine.
Saliva in the mouth can account for 30% of this initial starch digestion.
Saliva forms a protective film for the teeth and prevents dental caries and enamel breakdown.
Production of lysozyme and immunoglobulin A in the salivary glands, saliva plays an antimicrobial role against bacteria and viruses in the oral cavity.
Stimulated flow comes primarily from the parotid glands.
Stimulated flow can increase rate of flow by four fold from the parotid glands and a minor increase from the submandibular glands.
Flow regulated by central nervous system pathways and not by direct stimulation of the salivary glands.
Secretions are serous coming primarily from the parotid gland, mucous coming from the minor salivary glands and mixed coming from the submandibular and sublingual glands.
Serous secretions are more watery than the viscous saliva from mucous glands.
In the absence of intact cortical central nervous system connections taste and chewing do not increase salivary flow.