Anatomy, Head and Neck, Salivary Glands

Excerpt

The salivary glands are exocrine glands that make, modify and secrete saliva into the oral cavity. They are divided into two main types: the major salivary glands, which include the parotid, submandibular and sublingual glands, and the minor salivary glands, which line the mucosa of the upper aerodigestive tract and the overwhelming entirety of the mouth .

Human salivary glands produce between 0.5 to 1.5 L of saliva daily, facilitating mastication, swallowing, and speech, lubricating the oral mucosa, and providing an aqueous medium for taste perception. They also participate in the digestion of triglycerides and starches by secreting lipases and amylases. In addition, saliva plays a protective role against infections via its many organic constituents. These include the secretory piece, a glycoprotein that forms a complex with immunoglobulin A (IgA) to defend against viruses and bacteria, lysozymes that cause bacterial agglutination, autolysin to degrade bacterial cell walls, and lactoferrin to sequester iron (an element vital to bacterial growth) . Additionally, saliva contains ionic compounds, such as bicarbonates, that buffer acids produced by bacteria and protect the oral cavity and esophagus from gastric juice. As a result, saliva plays a vital role in protecting the mouth from chronic buccal mucosal infections and dental caries .