Morphological Analyses of the Human Tongue Musculature for Three-Dimensional Modeling

Abstract

Skilled movements of the tongue in speech articulation reflect complex formation of the tongue musculature, although its description in the anatomical literature is rather limited for developing a realistic computational model of the tongue. This study presents detailed descriptions of the muscular structure of the human tongue based on macroscopic and microscopic observations and provides three-dimensional schemata of the tongue musculature. Histologic examination revealed that the tongue consists of five strata, stacked along the courses of the fibers of the genioglossus muscle in proximal-distal directions. This stratum structure exists in the entire tongue tissue, indicating that the lingual musculature can be divided into the inner and outer regions. The former consisted of the "stem" and "core," and the latter of the "cover" and "fringe." In gross dissection, the tongue was cut into wedge-like blocks along the course of the genioglossus muscle to examine muscle fiber arrangement. Using this approach, it was determined that serial repetitions of "structural units" composed the inner musculature of the tongue. Each unit consisted of a pair of thin muscle fiber laminae; one was composed of the genioglossus and vertical muscles, and the other of the transverse muscle. In the apex, the laminae lacked the fibers of the genioglossus. These findings have been incorporated in three-dimensional schemata of the tongue musculature.

Coordinative Organization of Lingual Propulsion during the Normal Adult Swallow

“…The absence of a skeletal structure makes the tongue highly deformable. Shape changes are achieved by displacing the tongue's incompressible volume through contractions of a highly defined intrinsic muscular network [8]. Kier and Smith [9] classify this type of a movement system as a muscular hydrostat.…”

Internal Kinematics of the Tongue During Feeding in Pigs

“…longer on the entire muscle-based but grouped motor unit-based or segmented structure unit-based strategies (Slaughter et al, 2005;Sokoloff, 2004;Takemoto, 2001).…”

Three‐dimensional myoarchitecture of the bovine tongue demonstrated by diffusion spectrum magnetic resonance imaging with tractography

“…The tongue rests on a muscular floor composed of the geniohyoid muscle, which runs in the mid-sagittal plane from the mental spine of the mandible to the body of the hyoid bone, and the mylohyoid, which runs from the mylohyoid line of the mandible to the raphe and body of the hyoid bone. While these muscle delineations are readily apparent at the point of extrinsic attachment to bony surfaces, the distinction between the intrinsic and extrinsic musculature breaks down at the point of insertion into the tongue body (Depaul and Abbs, 1996;Mu and Sanders, 1999;Napadow et al, 2001;Takemoto, 2001;Wedeen et al, 2001). In fact, the tongue's myofibers become so extensively interwoven within its body that it may be appropriate to consider the tongue not as a set of anatomically discrete fibers, but as a continuous array of fibers with varying orientations and mechanical properties.…”