RESUMEN
In the sublingual/submandibular gland complex (L/M complex hereafter), the submandibular gland process adjoins the sublingual gland. Therefore, it is speculated that the L/M complex in the fused state is due to excessive development of the submandibular gland process. However, we encountered a case of the L/M complex formed due to supernumerary glandular lobes (lobes A, B, and C) developing in the posterior 1/3 portion of the submandibular duct. Lobes A, B, and C showed the following macroscopic morphologies, constitutions, ducts, and histological morphologies. Lobe A was disc-shaped, and this lobe together with the major sublingual gland was wrapped with the minor sublingual gland. Lobe B was attached to lobe C, forming a cingulate lobe. Lobe B had an irregular shape and was attached to the superior area of lobe A, while lobe C was rod-shaped and attached to the posterior area of lobe B. The posterior area of lobe C was attached to the submandibular gland at the base of the submandibular duct. The excretory ducts of lobes A, B, and C joined, forming one duct, which joined the posterior 1/3 portion of the submandibular duct. The histological morphologies of lobes A, B, and C showed a predominance of serous cells over mucous cells, which was the same as the morphology of the submandibular gland. In this case, the L/M complex may have formed by the following mechanism. Supernumerary lobes A, B, and C of the submandibular gland formed in the posterior 1/3 portion of the submandibular duct, and lobe A together with the major sublingual gland was wrapped with the minor sublingual gland. Lobes B and C formed a cingulate lobe, and its posterior portion (posterior portion of lobe C) attached to the submandibular gland, resulting in a fused state.
Asunto(s)
Glándula Sublingual/anomalías , Glándula Submandibular/anomalías , Anciano , Cadáver , Humanos , Masculino , Glándula Sublingual/patología , Glándula Submandibular/patologíaRESUMEN
The arrangement of the lingual muscles in the interior of the human tongue, particularly the course of the posterior muscle bundles of the styloglossus, was studied by gross anatomical examination and SEM, and its relationship with tongue functions was considered. The styloglossus divided into anterior and posterior fiber bundles. The bilateral anterior fiber bundles ran anteriorly, and fused at the median region of the lower surface of the tongue, forming a large arched structure. The posterior bundles divided into 10 or more smaller bundles and entered the interior of the tongue. These muscle bundles passed through the spaces between the inferior longitudinal and genioglossus and inserted in the lingual septum, forming a small arched structure. These posterior muscle bundles passed near the midpoint between the central third and dorsal third of the line between the mental spine and the dorsal surface of the tongue in the upper half of the root of the tongue, showing a multilayer structure. In many of the areas in which posterior muscle bundles were distributed, muscle bundles in the tongue were arranged along the posterior muscle bundles of the styloglossus, glossopharyngeal bundles of the superior pharyngeal constrictor muscle, and transverse muscle of the tongue from the deep layer to the dorsal surface of the tongue.
Asunto(s)
Músculo Esquelético/anatomía & histología , Lengua/anatomía & histología , Anciano , Anciano de 80 o más Años , Cadáver , Humanos , Procesamiento de Imagen Asistido por Computador , Microscopía Electrónica de Rastreo , Persona de Mediana Edad , Mucosa Bucal/anatomía & histología , Músculo Esquelético/ultraestructura , Paladar Blando/anatomía & histología , Faringe/anatomía & histología , Lengua/ultraestructuraRESUMEN
Intermediate morphologies between normal and anomalous morphologies of the superior belly of the omohyoid muscle (Om) were macroscopically and stereomicroscopically observed in 34 cadavers (24 males and 10 females aged between 51 and 97 years; average age 71.0 years) for anatomical practice, which had been preserved in the Department of Morphological Biology, Ohu University School of Dentistry. The intermediate morphologies were classified into four types on the basis of the developmental degree of the muscle fibers and the number and origin of the belly as follows: type 1, the anterior margin of the belly was unclear owing to poor myofiber development; type 2, the superior belly was composed of a posterior large belly and an anterior small belly; type 3, composed of three to five bellies, with the bellies arranged in a roof tile-like morphology; and type 4, the belly was composed of two bellies arranged anterior-posteriorly parallel to each other (the anterior belly was found to be the inferior belly that had developed and reached the superior belly area). For the intermediate morphologies of the Om superior belly observed in the present study, although type 4 was due to the development of an inferior belly, the other three types were considered to be caused by the poor development of the myofibers in the formation process and by the division of the superior belly into two muscles, or secondary lamellar division of the belly with growth.
Asunto(s)
Músculos del Cuello/anatomía & histología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Muscle bundles of the transverse and vertical muscles of the tongue become flat when they enter the longitudinal muscle layers of the tongue, where they form a tunnel-like structure that surrounds the longitudinal muscle of the tongue. However, the three-dimensional architecture of longitudinal muscle fibers of the tongue has not been clarified. In the present study, we evaluated the function of the intrinsic muscles of the tongue by studying the three-dimensional architecture of the longitudinal muscle. Muscle bundles of the longitudinal muscle of the anterior part of a rabbit's tongue were exposed by the chemical-maceration and modified chemical-maceration methods and examined by scanning electron microscopy. In the longitudinal muscle of the tongue, muscle bundles running in the anteroposterior direction were arranged at regular intervals. These muscle bundles bifurcated or ramified at a sharp angle at each level from the superficial layer to the deep layer and joined or fused with adjacent muscle bundles. In addition, these ramified muscle bundles ran obliquely into shallower or deeper layers of the muscle, as well as in the same plane. Consequently, the longitudinal muscle of the tongue as a whole had a three-dimensional mesh-like structure. The transverse and vertical muscles of the tongue entered this mesh-like structure of muscle bundles of the longitudinal muscle as flat muscle bundles. The transverse and vertical muscles showed no ramification in the center of the tongue, where there is no longitudinal muscle. These results suggest that the three intrinsic muscles of the tongue are interlaced with one another and are bound tightly in the longitudinal muscle. This structure may enable the dorsum of the tongue to harden for pressing food during mastication and shifting the food posteriorly for swallowing.