mouth

mouth, entrance to the digestive and respiratory tracts. The mouth, or oral cavity, is ordinarily a simple opening in lower animals; in vertebrates it is a more complex structure. In humans, the mouth is defined in front and at the sides by the lips, jawbone, teeth, and gums; in the rear it merges with the throat. The roof of the mouth is composed of the hard and soft palates and the floor of the mouth is formed by the tongue, a muscular structure that contains the organs of taste (taste buds). The lips, palates, tongue, and teeth are the major components in speech formation, using the "raw sound" formed in the larynx. The process of digestion begins in the mouth; the chewing and grinding action of the teeth reduces the food to a readily digestible substance. The enzymatic process of converting starch to sugar is initiated by salivary amylase (ptyalin) excreted by the three salivary glands located at the angle of the jawbone and under the tongue. Saliva produced in these glands moistens food, preparing it for processing in the digestive system.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on mouth from Fact Monster:

  • Foot-and-mouth Disease - Foot-and-mouth Disease FAQ Basics about the highly contagious disease by Ricco Villanueva Siasoco ...
  • MOUTH - Food enters the body through the mouth. The mouth is the first part of the digestive system, where food is mashed and moistened, so that it can be swa
  • foot-and-mouth disease - foot-and-mouth disease foot-and-mouth disease, highly contagious disease almost exclusive to ...
  • Why are our mouths dry in the morning? - Why are our mouths dry in the morning? When we sleep, we relax all our muscles, including our jaw ...
  • trench mouth - trench mouth trench mouth, common term for Vincent's infection, an ulcerative membranous ...

See more Encyclopedia articles on: Anatomy and Physiology