We examined morphological differences between the sublingual and submandibular glands with special reference to their innervation. The sublingual gland contained abundant periodic acid Schiff-positive mucous acini: some lobules were composed of purely mucous acini, while others were purely serous or mixed. However, in the submandibular gland, the area of mucous acini was very limited. Notably, in the sublingual gland, immunohistochemistry for neuron-specific enolase demonstrated that the serous acini carried a higher density of nerve elements than the mucous acini. However, no such difference was evident in the submandibular gland, possibly due to the small areas of the mucous acini. In both types of gland, neuronal nitric oxide synthase-positive parasympathetic nerves as well as tyrosine hydroxylase-positive sympathetic nerves were observed in the interlobular tissue, but we were unable to trace these thin fibers to the acini. Myoepithelial cells expressed smooth muscle actin, but were negative for S100B protein, glial fibrillary acidic protein and neuron-specific enolase. However, antibody against S100A stained some of the myoepithelial cells and ductal cells in the sublingual gland. Cells positive for peripheral myelin protein 22 were seen in some of the ductal cells in the submandibular gland, but not in the sublingual gland. Therefore, with regard to the neurogenic features of the gland cells, S100B reactivity might disappear first in postnatal life, whereas S100A reactivity is likely to remain as aging progresses. The sublingual gland in elderly individuals seems to provide a good model for comparison of the nerve supply between mucous and serous acini.
Actins ; Aged* ; Aging ; Cadaver* ; Glial Fibrillary Acidic Protein ; Humans ; Immunohistochemistry ; Muscle, Smooth ; Myelin Sheath ; Neurons ; Nitric Oxide ; Periodic Acid ; Phosphopyruvate Hydratase ; Sublingual Gland* ; Submandibular Gland ; Tyrosine

We compared the age-related morphology of the cricothyroid (CT) joint with that of the cricoarytenoid (CA) joint using 18 specimens from elderly cadavers in terms of their elastic fiber contents as well as the cells composing the joint capsule and synovial tissues. In contrast to an almost flat-flat interface in the CT joint, the CA joint was similar to a saddle joint. The CA joint capsule was thin and contained few elastic fibers, and in contrast to the CT joint, external fibrous tissues were not exposed to the joint cavity, there being no injury to the CA joint capsule. The lateral and posterior aspects of the CA joint were covered by the lateral and posterior CA muscles, respectively, and the fascia of the latter muscle was sometimes thick with abundant elastic fibers. However, due to possible muscle degeneration, loose connective tissue was often interposed between the fascia and the capsule. The medial and anterior aspects of the CA joint faced loose tissue that was continuous with the laryngeal submucosal tissue. Therefore, in contrast to the CT joint, a definite supporting ligament was usually absent in the CA joint. Synovial folds were always seen in the CA joint, comprising a short triangular mass on the posterior side and long laminar folds on the anterior side. The synovial folds usually contained multiple capillaries and a few CD68-positive macrophages. High congruity of the CA joint surfaces as well as strong muscle support to the arytenoid cartilage appeared to provide the specific synovial morphology.
Aged* ; Arytenoid Cartilage ; Cadaver ; Capillaries ; Connective Tissue ; Elastic Tissue ; Fascia ; Humans ; Joint Capsule ; Joints* ; Ligaments ; Macrophages ; Muscles

Macrophages play an important role in aging-related muscle atrophy (i.e., sarcopenia). We examined macrophage density in six striated muscles (cricopharyngeus muscle, posterior cricoarytenoideus muscle, genioglossus muscle, masseter muscle, infraspinatus muscle, and external anal sphincter). We examined 14 donated male cadavers and utilized CD68 immunohistochemistry to clarify macrophage density in muscles. The numbers of macrophages per striated muscle fiber in the larynx and pharynx (0.34 and 0.31) were 5–6 times greater than those in the tongue, shoulder, and anus (0.05–0.07) with high statistical significance. Thick muscle fibers over 80 µm in diameter were seen in the pharynx, larynx, and anal sphincter of two limited specimens. Conversely, in the other sites or specimens, muscle fibers were thinner than 50 µm. We did not find any multinuclear muscle cells suggestive of regeneration. At the beginning of the study, we suspected that mucosal macrophages might have invaded into the muscle layer of the larynx and pharynx, but we found no evidence of inflammation in the mucosa. Likewise, the internal anal sphincter (a smooth muscle layer near the mucosa) usually contained fewer macrophages than the external sphincter. The present result suggest that, in elderly men, thinning and death of striated muscle fibers occur more frequently in the larynx and pharynx than in other parts of the body.
Aged* ; Anal Canal ; Cadaver* ; Deglutition ; Deglutition Disorders ; Humans ; Humans* ; Immunohistochemistry ; Inflammation ; Laryngeal Muscles* ; Larynx ; Macrophages* ; Male ; Masseter Muscle ; Mucous Membrane ; Muscle Cells ; Muscle, Smooth ; Muscle, Striated* ; Muscles ; Muscular Atrophy ; Pharynx ; Regeneration ; Sarcopenia ; Shoulder ; Tongue

There is little or no information about the distribution of elastic fibers in the human fetal head. We examined this issue in 15 late-stage fetuses (crown-rump length, 220-320 mm) using aldehyde-fuchsin and elastica-Masson staining, and we used the arterial wall elastic laminae and external ear cartilages as positive staining controls. The posterior pharyngeal wall, as well as the ligaments connecting the laryngeal cartilages, contained abundant elastic fibers. In contrast with the sphenomandibular ligament and the temporomandibular joint disk, in which elastic fibers were partly present, the discomalleolar ligament and the fascial structures around the pterygoid muscles did not have any elastic fibers. In addition, the posterior marginal fascia of the prestyloid space did contain such fibers. Notably, in the middle ear, elastic fibers accumulated along the tendons of the tensor tympani and stapedius muscles and in the joint capsules of the ear ossicle articulations. Elastic fibers were not seen in any other muscle tendons or vertebral facet capsules in the head and neck. Despite being composed of smooth muscle, the orbitalis muscle did not contain any elastic fibers. The elastic fibers in the sphenomandibular ligament seemed to correspond to an intermediate step of development between Meckel's cartilage and the final ligament. Overall, there seemed to be a mini-version of elastic fiber distribution compared to that in adults and a different specific developmental pattern of connective tissues. The latter morphology might be a result of an adaptation to hypoxic conditions during development.
Adult ; Capsules ; Cartilage ; Connective Tissue ; Ear Cartilage ; Ear Ossicles ; Ear, Middle ; Elastic Tissue ; Fascia ; Fetus ; Head ; Humans ; Joint Capsule ; Laryngeal Cartilages ; Ligaments ; Muscle, Smooth ; Muscles ; Neck ; Pterygoid Muscles ; Stapedius ; Temporomandibular Joint Disc ; Tendons ; Tensor Tympani

To provide a better understanding of the local immune system in the face and external genitalia, i.e., the oral floor, lower lip, palpebral conjunctiva, anus and penis, we examined the distribution and density of CD1a-positve Langerhans cells, CD8-positive suppressor T lymphocytes and CD68-positive macrophages using specimens from 8 male elderly cadavers. The density of Langerhans cells showed an individual difference of more than (or almost) 10-fold in the lip (oral floor). In the oral floor, Langerhans cells were often spherical. Submucosal or subcutaneous suppressor lymphocytes, especially rich in the oral floor and penile skin, migrated into the epithelium at 4 sites, except for the anus. In the conjunctiva, macrophage migration into the epithelium was seen in all 8 specimens. The density of suppressor lymphocytes showed a significant correlation between the oral floor and the lip (r=0.78). In contrast, the anal and penile skins showed no positive correlation in the density of all three types of immunoreactive cells examined. Overall, irrespective of the wide individual differences, the oral floor and conjunctiva seemed to be characterized by a rich content of all three cell types, whereas the penile skin was characterized by an abundance of suppressor lymphocytes. Based on the tables, as mean value, the relative abundance of three different cell types were as follows; CD1a-positive Langerhans cells (anus), CD8-positive lymphocytes (penis), and CD68-positive macrophages (lip). The present observations suggest that the local immune response is highly site-dependent, with a tendency for tolerance rather than rejection.
Aged* ; Anal Canal ; Cadaver* ; CD8-Positive T-Lymphocytes ; Conjunctiva ; Epithelium ; Genitalia ; Humans ; Immune System ; Individuality ; Langerhans Cells* ; Lip ; Lymphocytes ; Macrophages* ; Male ; Penis ; Skin ; T-Lymphocytes*