Anatomy and Physiology of Children and Adolescents - M. R. Sapin 2007

The Science of Internal Organs (Splanchnology)
Digestive System
Oral Cavity - Tongue

The Tongue is a muscular organ formed by Striated Muscle tissue covered with a mucous membrane. It is involved in food mixing, swallowing, and speech articulation, and also serves as The ORGAN OF TASTE. In infants, the tongue plays a crucial role in suckling. Its lateral borders are known as the margins, the narrow anterior portion is called the apex (tip), and the broad posterior portion is the base (ROOT). The middle section between the apex and the base forms the body of the tongue, and its upward-facing surface is referred to as the dorsum.

The mucous membrane of the tongue, covered with stratified non-keratinized epithelium, features numerous papillae of various shapes: filiform, conical, foliate, fungiform, and vallate (circumvallate). Filiform papillae are the most abundant, measuring approximately 0.3 mm in length, and give the dorsum of the tongue a velvety appearance. These papillae contain nerve endings that perceive tactile sensations. Foliate papillae are located along the lateral margins of the tongue. Fungiform papillae are fewer in number than filiform ones, but larger, ranging from 0.7 to 1.8 mm in length. Vallate papillae, numbering 7 to 12, are surrounded by a trench and wall, and are situated at the boundary between the dorsum and the Base of the tongue. Taste buds—clusters of receptor Cells—are embedded within the epithelium of the foliate, fungiform, and vallate papillae.

The mucosal surface of the root of the tongue is irregular due to accumulations of lymphoid tissue in its lamina propria, which form the lingual tonsil, an organ belonging to The Immune System.

The Muscles of the tongue are divided into extrinsic and intrinsic groups. The extrinsic muscles are paired and include the genioglossus, hyoglossus, and styloglossus. These muscles originate from the BONES OF THE Skull base and insert into the substance of the tongue, moving it in various directions. The intrinsic muscles originate and insert entirely within the tongue. They consist of bundles of longitudinal, transverse, and vertical muscle fibers that intertwine with one another and with the fibers of the extrinsic muscles. Contraction of the intrinsic muscles alters the shape of the tongue, making it shorter and thicker or broader and flatter.