saliva

(noun)

A clear, slightly alkaline liquid secreted into the mouth by the salivary glands and mucous glands that consists of water, mucin, protein, and enzymes. It moistens the mouth, lubricates ingested food, and begins the breakdown of starches.

Related Terms

Examples of saliva in the following topics:

  • Ingestion

    • The first step to obtaining nutrition is ingestion, a process where food is taken in through the mouth and broken down by teeth and saliva.
    • Once in the mouth, the teeth, saliva, and tongue play important roles in mastication (preparing the food into bolus).
    • While the food is being mechanically broken down, the enzymes in saliva begin to chemically process the food as well.

  • Digestive System: Mouth and Stomach

    • As food is chewed, saliva, produced by the salivary glands, mixes with the food.
    • Saliva is a watery substance produced in the mouths of many animals.
    • Saliva contains mucus that moistens food and buffers the pH of the food.
    • Food is masticated by teeth and moistened by saliva secreted from the (b) salivary glands.
    • Enzymes in the saliva begin to digest starches and fats.

  • Dental Caries

    • If demineralization exceeds saliva and other remineralization factors such as from calcium and fluoridated toothpastes, these tissues progressively break down, producing dental caries (cavities, holes in the teeth) .
    • To be specific, a tooth (which is primarily mineral in content) is in a constant state of back-and-forth demineralization and remineralization between the tooth and surrounding saliva.
    • For people with little saliva, especially due to radiation therapies that may destroy the salivary glands, there also exists remineralization gel.
    • All caries occur from acid demineralization that exceeds saliva and fluoride remineralization, and almost all acid demineralization occurs where food (containing carbohydrate like sugar) is left on teeth.
    • The process is dynamic, however, as remineralization can also occur if the acid is neutralized by saliva or mouthwash.

  • Mouth

    • The mouth receives and mechanically breaks down food, produces saliva, and is the first portion of the alimentary canal.
    • It receives food and moistens the food with saliva, while the food is mechanically processed (mastication) by the teeth.
    • Saliva is projected from three main pairs of salivary glands: the large parotid glands near the cheeks, the submandibular glands beneath the mandible, and the sublingual glands beneath the tongue.
    • Saliva keeps the mouth moist and lubricates the food, helping the tongue form the food into a soft wad, called a bolus.
    • The fluid of saliva also contains several enzymes, notably lysozyme—an antibacterial agent—and amylase, which catalyzes large starch molecules into simpler sugars via hydrolysis.

  • Sjögren's Syndrome

    • Sjögren's syndrome is an autoimmune disease in which immune cells attack and destroy the exocrine glands that produce tears and saliva.
    • Sjögren's syndrome, also known as "Mikulicz disease" and "Sicca syndrome," is a systemic autoimmune disease in which immune cells attack and destroy the exocrine glands that produce tears and saliva.
    • An alternative test is nonstimulated whole saliva flow collection, in which the patient spits into a test tube every minute for 15 minutes.
    • Preventive dental treatment is also necessary, as the lack of saliva associated with dry mouth creates an ideal environment for the proliferation of bacteria that cause dental cavities.

  • Basic Principles of Classical Conditioning

    • When a dog sees food, the visual and olfactory stimuli send information to the brain through their respective neural pathways, ultimately activating the salivation glands to secrete saliva.
    • This reaction is a natural biological process as saliva aids in the digestion of food.

  • Processes and Functions of the Digestive System

    • A brain reflex triggers the flow of saliva when we see or even think about food.
    • Enzymes in saliva then begin the chemical breakdown of food; teeth aid in the mechanical breakdown of larger food particles.
    • Saliva moistens the food, while the teeth masticate the food and make it easier to swallow.
    • To accomplish this moistening goal, the salivary glands produce an estimated three liters of saliva per day.
    • Amylase, the digestive enzyme found in saliva, starts to break down starch into simple sugars before the food even leaves the mouth.

  • Neural Responses to Food

    • The salivary glands secrete more saliva in response to the stimulus presented by food in preparation for digestion.
    • Seeing a plate of food triggers the secretion of saliva in the mouth and the production of hydrochloric acid in the stomach.

  • Immediate Direct Examination of Specimen

    • For example, throat and nasopharyngeal swabs should not touch the tongue, cheek, or saliva.
    • Saliva is an especially undesirable contaminant because it contains millions of bacteria, of which are normal flora.
    • Sputum, the mucous secretion that coats the lower respiratory surfaces, especially the lungs, is discharged by coughing or taken by a catheterization to avoid contamination with saliva.

  • Digestion in the Mouth, Pharynx, and Esophagus

    • When food enters the mouth, digestion begins with the action of mastication, a form of mechanical digestion, and with the contact of saliva.
    • Saliva is secreted in large amounts (1-1.5 liters per day) by three pairs of exocrine salivary glands (parotid, submandibular, and sublingual) in the oral cavity, and is mixed with the chewed food by the tongue.