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).

Glossitis

Glossitis is a condition characterized by a swollen, smooth-looking tongue that has changed color, commonly to an unusually dark red color. Glossitis is also called smooth tongue and burning tongue syndrome. Glossitis can occur alone, or it can be caused by diseases, disorders and conditions that may lead to serious complications in some cases. Glossitis can result from infection, inflammation, allergy, trauma, and certain disorders, such as anemia.