Final answer:
Secretions from the intrinsic salivary glands, which include minor glands throughout the oral mucosa, mainly contribute lingual lipase for the initial digestion of fats, adding to the overall saliva composition.
Step-by-step explanation:
The secretions from the intrinsic salivary glands, also known as minor salivary glands, contribute to the overall composition of saliva in the mouth. Unlike the major salivary glands (parotid, submandibular, and sublingual glands), these minor glands are distributed throughout the oral mucosa including the lips, cheeks, palate, and tongue. While the major glands primarily secrete salivary amylase, involved in the initial digestion of carbohydrates, the minor glands, particularly those on the tongue, are responsible for secreting lingual lipase, an enzyme that initiates the digestion of fats. Despite their smaller size, these intrinsic glands are significant as they secrete saliva continually, aiding in lubrication and the initiation of digestion.