Language

Language (lingua) participates in the mechanical processing of food, in the act of swallowing, in taste perception, in the articulation of speech. The tongue is located in the oral cavity. It is a flattened, flattened muscular organ. The tongue tapers in front, forming the apex of the tongue (apex linguae). The apex of the back passes into the broad and thick body of the tongue (corpus linguae), behind which lies the root of the tongue (radix linguae). The upper, convex surface is called the back of the tongue (dorsum linguae). The lower surface (facies inferior linguae) is only in front of the tongue. On each side the tongue is bounded by the right and left rounded margins (margo linguae). A midline of the tongue (sulcus medianus linguae) extends from the median line from front to back. In the thickness of the tongue, it corresponds to a fibrous plate that divides the tongue into the right and left halves. The median furrow ends in a blind hole (foramen caecum). A lateral furrow (sulcus terminalis), in the form of the letter V, is directed to the side of this hole and laterally. The furrow separates the body and the root of the tongue. In the area of the root of the tongue is an important immune organ - lingual tonsil.

The mucous membrane outside covers the muscles of the tongue. The surface of the mucous membrane of the tongue is velvety because of the presence of numerous papillae (papillae linguales). Each papilla represents an outgrowth of its own plate of the mucous membrane of the tongue, covered with multilayered flat epithelium. In the connective tissue of the papillae there are numerous blood capillaries, in the epithelial cover sensitive sensory nerve endings are located.

Filamentous and conical papillae (papillae filiformis and papillae conicae), the most numerous, are diffusely located in the region of the entire back of the tongue, have a length of about 0.3 mm. Mushroom papillae (papillae fungi formis) are located mainly on the top and along the edges of the tongue. Their base is narrowed, and the apex is enlarged. The length of these papillae is 0.7-1.8 mm, the diameter is 0.4-1.0 mm. In the thickness of the epithelium of the mushroom papillae there are taste buds (3-4 in each papilla), having taste sensitivity. Tubular papillae (papillae vallatae), or papillae surrounded by a shaft, in number 7-12 are located on the border of the body and root of the tongue, anterior to the border groove. The length of the groove papillae is 1-1.5 mm, the diameter is 1-3 mm. Tubular papillae have a narrow base and an enlarged, flattened free part. Around the papilla is an annular groove (groove) separating the papilla from the surrounding thickened cushion. In the epithelium of the lateral surfaces of the trough-shaped papilla and the surrounding roller there are numerous taste buds.

Leaf papillae (papillae foliatae) in the form of flat plates 2-5 mm in length are located on the edges of the tongue; they also contain taste buds.

The mucous membrane of the tongue is not uniform in different departments. In the region of the back of the tongue, it is devoid of the submucosa of the base and immovably fused with the muscular base of the tongue. The mucous membrane of the root has numerous depressions and elevations, under it lies the lingual amygdala. A well developed submucosa base of the lower surface of the tongue contributes to the formation of folds. At the tip of the tongue two fringe folds (plicae fimbriatae) are formed. When moving from the lower surface of the tongue to the bottom of the oral cavity along the median line, the mucosa forms a sagittally oriented fold - the frenulum linguae (frenulum linguae). On the sides of the bridle on the elevation is a paired hyoid papilla (caruncula sublingualis). On the sublingual papilla, the excretory ducts of the submerged-non-maxillary and sublingual salivary glands of the corresponding side are opened. Behind the hyoid papilla is a longitudinal sublingual fold (plica sublingualis), under which lies the epithelium of the same name.