Compositional changes of the muscular layers of the stomach with aging

To elucidate compositional changes of the stomach with aging, the authors investigated age-related changes of the elements and relationships among the elements in the muscular layers of the pylorus, cardia, lesser curvature, and greater curvature by inductively coupled plasma-atomic emission spectrometry. After ordinary dissection by medical students, the pylori, cardias, lesser curvatures, and greater curvatures were removed from the subjects, consisting of 19 men and 1 woman, ranging in age from 65 to 95 yr. The muscular layers were isolated and the element contents were determined.The calcium content increased progressively with aging in the muscular layers of the pylorus, cardia, and lesser curvature, whereas it tended to increase in the muscular layer of the greater curvature with aging. Regarding sulfur, the content increased significantly in the muscular layer of the pylorus with aging, but not significantly in the muscular layers of the cardia, lesser curvature, and greater curvature with aging.Regarding the relationships among the elements, significant direct correlations were found among calcium, phosphorus, sulfur, and magnesium in both the muscular layers of the pylori and cardias, with some exceptions.     

Morphological analyses and 3D modeling of the tongue musculature of the chimpanzee (Pan troglodytes)

Knowledge of the comparative anatomy of tongue musculature is crucial to the discussion of the origin and the evolution of speech because of the indispensable role played by this organ in speech. However, the tongue musculature of primates has rarely been studied. In a previous study, the author analyzed human tongue musculature and developed a 3D model of this organ [Takemoto, Journal of Speech, Language, and Hearing Research 44:95-107, 2001]. In this study, the tongue musculature of chimpanzees was examined using methods similar to those used for humans. Results showed that tongue musculature was topologically the same for both humans and chimpanzees. As in humans, the tongue musculature of chimpanzees consisted of inner and outer regions. The inner musculature was composed of serial "structural units," made up of two types of laminae whose fibers were perpendicular to the tongue surface. The outer musculature was a thin layer of fibers oriented parallel to the surface and superficial to the inner musculature. Although the tongue musculature of humans and chimpanzees is similar, the external shapes differ: the chimpanzee tongue is flat, whereas the human tongue is round. Applying the muscular hydrostat theory to the external shape of the tongue suggests that the primary actions of the chimpanzee tongue are protrusion and retrusion, whereas the human tongue can be deformed in the oral cavity with a high degree of freedom. It is hypothesized that the evolution of the external shape of the tongue is one of the factors that led to the development of human speech. The results of this study suggest that modeling based on muscular hydrostatic theory of the effects of changes in external tongue shape on articulatory movements should be included in discussions on the origin of speech.     

Muscular system in polychaetes (Annelida)

The structure of the polychaete muscular system is reviewed. The muscular system comprises the muscles of the body wall, the musculature of the parapodial complex and the muscle system of the dissepiments and mesenteries. Various types of organisation of the longitudinal and circular components of the muscular body wall are distinguished. In Opheliidae, Polygordiidae, Protodrilidae, Spionidae, Oweniidae, Aphroditidae, Acoetidae (=Polyodontidae), Polynoidae, Sigalonidae, Phyllodocidae, Nephtyidae, Pisionidae, and Nerillidae circular muscles are lacking. It is hypothesised that the absence of circular muscles represents the plesiomorphic state in Annelida. This view contradicts the widely accepted idea of an earthworm-like musculature of the body wall comprising an outer layer of circular and an inner layer of longitudinal fibres. A classification of the various types of parapodial muscle construction has been developed. Massive and less manoeuvrable parapodia composed of many components like those of Aphrodita are regarded to represent the plesiomorphic state in recent polychaetes. An analysis of the diversity of the muscular structure supports the hypothesis that the primary mode of life in polychaetes was epibenthic and the parapodial chaetae had a protective function.     

Musculature of the penial complex: A new criterion in unravelling the phylogeny of Hygrophila (Gastropoda: Pulmonata)

The taxonomy of freshwater pulmonates (Hygrophila) has been in a fluid state warranting the search for new morphological criteria that may show congruence with molecular phylogenetic data. We examined the muscle arrangement in the penial complex (penis and penis sheath) of most major groups of freshwater pulmonates to explore to which extent the copulatory musculature can serve as a source of phylogenetic information for Hygrophila. The penises of Acroloxus lacustris (Acroloxidae), Radix auricularia (Lymnaeidae), and Physella acuta (Physidae) posses inner and outer layers of circular muscles and an intermediate layer of longitudinal muscles. The inner and outer muscle layers in the penis of Biomphalaria glabrata consist of circular muscles, but this species has two intermediate longitudinal layers separated by a lacunar space, which is crossed by radial and transverse fibers. The muscular wall of the penis of Planorbella duryi is composed of transverse and longitudinal fibers, with circular muscles as the outer layer. In Planorbidae, the penial musculature consists of inner and outer layers of longitudinal muscles and an intermediate layer of radial muscles. The penis sheath shows more variation in muscle patterns: its muscular wall has two layers in A. lacustris, P. acuta, and P. duryi, three layers in R. auricularia and Planorbinae and four layers in B. glabrata. To trace the evolution of the penial musculature, we mapped the muscle characters on a molecular phylogeny constructed from the concatenated 18S and mtCOI data set. The most convincing synapomorphies were found for Planorbinae (inner and outer penis layers of longitudinal muscles, three-layered wall of the penis sheath). A larger clade coinciding with Planorbidae is defined by the presence of radial muscles and two longitudinal layers in the penis. The comparative analysis of the penial musculature appears to be a promising tool in unraveling the phylogeny of Hygrophila.     

The nervous system of Tricladida. I. Neuroanatomy ofProcerodes littoralis (Maricola,Procerodidae): An immunocytochemical study

The organization of the nervous system ofProcerodes littoralis (Tricladida, Maricola, Procerodidae) was studied by immunocytochemistry, using antibodies to authentic flatworm neuropeptide F (NPF) (Moniezia expansa). Compared to earlier investigations of the neuroanatomy of tricladid flatworms, the pattern of NPF immunoreactivity inProcerodes littoralis reveals differences in the following respects: 1. Shape and structure of the brain. 2. Number and composition of longitudinal nerve cords. 3. Shape of branches of, and transverse connections between, main ventral nerve cords. 4. Composition of the pharyngeal nervous system. The rich innervation by NPF immunoreactive (IR) fibres and cells of the subepithelial muscle layer, the pharynx musculature and the musculature of the male copulatory apparatus indicates a neurotransmitter or neuromodulatory influence on muscular activity.     

Myoanatomy of the marine tardigrade Halobiotus crispae (Eutardigrada: Hypsibiidae)

The muscular architecture of Halobiotus crispae (Eutardigrada: Hypsibiidae) was examined by means of fluorescent‐coupled phalloidin in combination with confocal laser scanning microscopy and computer‐aided three‐dimensional reconstruction, in addition to light microscopy (Nomarski), scanning electron microscopy, and transmission electron microscopy (TEM). The somatic musculature of H. crispae is composed of structurally independent muscle fibers, which can be divided into a dorsal, ventral, dorsoventral, and a lateral musculature. Moreover, a distinct leg musculature is found. The number and arrangement of muscles differ in each leg. Noticeably, the fourth leg contains much fewer muscles when compared with the other legs. Buccopharyngeal musculature (myoepithelial muscles), intestinal musculature, and cloacal musculature comprise the animal's visceral musculature. TEM of stylet and leg musculature revealed ultrastructural similarities between these two muscle groups. Furthermore, microtubules are found in the epidermal cells of both leg and stylet muscle attachments. This would indicate that the stylet and stylet glands are homologues to the claw and claw glands, respectively. When comparing with previously published data on both heterotardigrade and eutardigrade species, it becomes obvious that eutardigrades possess very similar numbers and arrangement of muscles, yet differ in a number of significant details of their myoanatomy. This study establishes a morphological framework for the use of muscular architecture in elucidating tardigrade phylogeny. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.     

Muscular anatomy of the millipede Phyllogonostreptus nigrolabiatus (Diplopoda: Spirostreptida) and its bearing on the millipede "thorax"

The muscular anatomy of the millipede Phyllogonostreptus nigrolabiatus (Newport, 1844) (Diplopoda; Spirostreptida; Harpagophoridae) is comprehensively surveyed. The musculature of the first three postcollum pleurotergites, the "thorax," and their associated appendages was found to be more complex than that of the postthoracic rings. It is hypothesized that the musculature of the postthoracic segments is derived relative to that of the thoracic segments, which retain primitively free sternites and are not diplosegments. This hypothesis is discussed relative to previous hypotheses positing that the anteriormost three leg-bearing rings in millipedes are diplosegments. The musculature of spirostreptid gonopods is described in detail for the first time. Comparison of the cephalic musculature is made with previously described musculature in Julida showing that, while many aspects of the musculature are conserved, there exist interordinal differences, documenting the potential utility of comparative anatomical studies for resolving millipede phylogeny.     

A new morpho-functional classification of the Fallopian tube based on its three-dimensional myoarchitecture

The recent direct observations, under scanning electron microscopy (SEM), of the three-dimensional architecture of myosalpinx in different mammals allows us classify salpinxes according to the myoarchitecture of their tubo-uterine junction (TUJ) and isthmus segments. Based upon the myoarchitecture of the outer wall of the TUJ we could find barrier-like species (rat and sow), sphincter-like species type a (rabbit and ewe) and sphincter-like species type b (cow and woman). The different architecture of TUJ can be explained by the different nature of the mating process. Based upon the myoarchitecture of the isthmus we could distinguish type 1 (rat) and type 2 (rabbit, ewe, sow, cow and woman) salpinxes. In the latter the close fusion of musculature deriving from the meso (extrinsic musculature) with the musculature of salpinx (intrinsic musculature) suggests the existence of a unique mesosalpinx contractile system. The myosalpinx is mostly made up of a single network of muscular fibers. Such a plexiform structure, owing to the uneven distribution of fibers, rather than producing a series of regular contraction waves, is more likely to generate random contraction waves. The random propagation of muscular network contraction may deform the plexiform wall of the myosalpinx causing the stirring of tubal contents. By such a stirring movement the contact between hormones and nutrients and the eggs or embryos is intensified, thus favoring a correct fertilization and early embryo development. Taken all together, these systematic results probably suggest an additional and rather new function for the musculature of the tube, namely to increase fertility in a large number of species.     

Altricial and precocial mammals: A model of neural and muscular development

This model of growth offers a quantitative definition for altricial and precocial newborns, makes muscular strength a benchmark for locomotor independence, and discriminates related genera as well as genera across major taxonomic divides. The model contrasts four theoretical conditions of the neonate (I, small brain, weak musculature; II, small brain, strong musculature; III, large brain, weak musculature; IV, large brain, strong musculature) with species from three orders of placental mammal. Each species exhibits a distinct mother-infant strategy from the altricial red panda cub (condition I) and the golden lion tamarin (condition III) to the precocial wildebeest calf (condition IV). The model proposes that early growth rates of brain and muscle correlate with nutrition, maternal effort during gestation and lactation, and parental care, whereas postnatal muscular growth correlates directly with adult body size and locomotor repertoire. An example of condition II (small brain, strong musculature) has not been found. This suggests that muscle does not grow in advance of the brain and that the brain acts as a pacemaker of growth. In order to increase our understanding of exotic species, noninvasive measures (body weight and length) and observations (opening of the eyes and ears, hair density, weaning, and the abilities to ther-moregulate and to move) should be supplemented with analysis of the differential tissue and organ growth. In both theoretical and practical ways analysis of deceased individuals contributes to the understanding of all species.     

Development of the external muscle coats in the digestive tract of the opossum, Didelphis virginiana

Development of the external musculature of the gastrointestinal tract has been studied in the stomach, small intestine and colon of the postnatal opossum. The muscle support is thin and poorly developed at birth, especially in the stomach and small intestine where only the inner layer is completely formed. The outer layer is discontinuous and formed by scattered myoblasts. The muscularis externa of the colon at birth is considerably thicker and both layers are present. Subsequent development of the muscularis externa consists of an early period of proliferative activity followed by hypertrophy. A low rate of mitotic activity continues throughout development and into the adult. Elements of the myenteric plexus are present at birth.     

An ultrastructural analysis of the salivary system of the terrestrial mollusc, Limax maximus.

The bilateral salivary glands, ducts, and nerves of the giant garden slug Limax maximus control the secretion of saliva and its transport to the buccal mass. Each salivary nerve, which originates at the buccal ganglion, contains over 3000 axon profiles. The axons innervate the musculature of the duct and branch within the gland. The salivary duct is composed of several muscular layers surrounding an epithelial layer which lines the duct lumen. The morphology of the duct epithelium indicates that it may function in ion or water balance. The salivary gland contains four major types of secretory cells. The secretory products are released from vacuoles in the gland cells, and are presumably transported by cilia in the collecting ducts of the gland into the larger muscular ducts.     

几种激素在鳜胃肠道内分泌细胞中存在的免疫细胞化学证据

用链酶亲和素－生物素过氧化物酶（Strept Avidin-Biotin-Complex,SABC）免疫细胞化学方法,使用4种兔抗消化 道激血清对鳜胃肠道中的内分泌细胞进行鉴别和定位。结果在鳜鱼胃的贲门、幽门及肠道中均发现不同程度地存在着生长抑素和五羟色胺免疫活性内分泌细胞。在鳜的贲门上皮和贲门腺之间,幽门上皮和幽门腺之间均分布有生长抑素免疫活性阳性细胞,在贲门腺和幽门腺处的分布较密。这些含五羟色胺的肽能神经元具有典型的APUD（Amine Precursor Uptake and Decarboxylation）细胞特征,提示鱼类的胃肠道同哺乳动物的胃肠道一样富含肽能神经元;为神经－内分泌系统的研究提供有力的形态学依据,另外两种抗血清－高血糖素和胃泌素的免疫细胞化学染色在鳜的胃肠道的各部位均未发现阳性反应。     

Phospholipid content in the compact and spongious musculature of the carp heart (Cyprinus carpio)

The phospholipid content of the spongious and compact musculature of the heart of the carp (Cyprinus carpio) was compared. The content of phospholipids is higher in the spongious musculature, the greatest difference being in the content of diphosphatidylglycerol: 2.53 mumol P . g-1 wet weight in the spongious layer and 1.29 mumol P . g-1 wet weight in the compact one. In both tissues plasmalogens represent 20-27% of the tissue content of choline and ethanolamine phosphoglycerides.     

rAAV6-microdystrophin preserves muscle function and extends lifespan in severely dystrophic mice

Mice carrying mutations in both the dystrophin and utrophin genes die prematurely as a consequence of severe muscular dystrophy. Here, we show that intravascular administration of recombinant adeno-associated viral (rAAV) vectors carrying a microdystrophin gene restores expression of dystrophin in the respiratory, cardiac and limb musculature of these mice, considerably reducing skeletal muscle pathology and extending lifespan. These findings suggest rAAV vector-mediated systemic gene transfer may be useful for treatment of serious neuromuscular disorders such as Duchenne muscular dystrophy.     

Some regularities of the regeneration of the musculature of internal organs]

The paper summarizes the data of the author and his co-workers on regulation of the musculature of vessels, digestive tract, uterus, ureters and urinary bladder. The smooth muscle cells have different degrees of differentiation. The muscular tissue of the vessels is most differentiated. The uterus musculature is very plastical. After injury mature myocytes are the first to undergo destruction. The intermedial substance is more stable. Myoblasts, young elements of the fibroblast row and the subendothelial layer cells are the origin of muscular regeneration. Figures of mitosis and amitosis are noted. Mature myocytes and intercellular substance are formed in the process of differentiation of the regeneration. The content of RNP in the regeneration cells is high, but in the process of differentiation of its elements it becomes lower. The DNP level has inconsiderable fluctuations. In early experiments PAS-positive substances are revealed in greater degree than in later ones. The content of acid mucopolysaccharides decreases in the process of fibrillogenesis. In all internal organs under study the muscular tissue regenerated. The degree of differentiation, severity of the lesion and functional peculiarities of the organ determine the completeness of the tissue reparation. The musculature of the intestinal tract and vessels regenerates more completely. Mighty layers of connective tissue with de novo formed blood vessels are disposed among the bundles of the repaired muscular tissue of the uterus and urine bladder wall. Simultaneously a part of regeneration cells are destroyed. These are two sides of a single process of development.     

Morphohistochemical and electrophysiological characteristics of the transverse striated muscles of the rabbit esophagus

A specific histochemical profile of the muscular tunic of the stomach has been revealed; its myons demonstrate a high succinate dehydrogenase and myofibrillar ATPase activity. Electrical activity of the oesophageal musculature has common features with biopotentials of the skeletal muscles and the smooth musculature of the stomach. The similiarity with the skeletal muscle biopotentials is evident as a peculiar spike activity, especially at the time of feeding. In electrograms of the striated oesophageal muscles slow waves are seen; they change at deprivation and feeding. Therefore, it is possible to compare them with the smooth musculature capable to generate slow waves.     

The facial expression musculature in primates and its evolutionary significance

Facial expression is a mode of close-proximity non-vocal communication used by primates and is produced by mimetic/facial musculature. Arguably, primates make the most-intricate facial displays and have some of the most-complex facial musculature of all mammals. Most of the earlier ideas of primate mimetic musculature, involving its function in facial displays and its evolution, were essentially linear "scala natural" models of increasing complexity. More-recent work has challenged these ideas, suggesting that ecological factors and social systems have played a much larger role in explaining the diversity of structures than previously believed. The present review synthesizes the evidence from gross muscular, microanatomical, behavioral and neurobiological studies in order to provide a preliminary analysis of the factors responsible for the evolution of primate facial musculature with comparisons to general mammals. In addition, the unique structure, function and evolution of human mimetic musculature are discussed, along with the potential influential roles of human speech and eye gaze.