bluuebunny/crossref_metadata_2025_split huggingface dataset:
Architecture of the hind limb muscles of cats: Functional significance
Authors: Sacks Robert D. , Roy Roland R. 
Published: February 2005

AbstractForce, velocity, and displacement properties of a muscle are determined in large part by its architectural design. The relative effect of muscle architecture on these physiological variables was studied by determining muscle weight, fiber length, average sarcomere length, and approximate angle of pinnation for 24 cat hind limb muscles. Muscle lengths ranged from 28.3 to 144 mm, whereas fiber lengths ranged from 8.4 to 105.5 mm. Generally, fiber to muscle length ratios were similar throughout a muscle. Estimated angles of pinnation of muscle fibers varied from 0 to 21° with most having an angle of less than 10°. The cross‐sectional area of the knee extensors was similar to the knee flexors (16.43 vs. 16.83 cm2) whereas the cross‐sectional area of the ankle extensors was more than six times greater than the ankle flexors (18.59 vs. 2.83 cm2). There was a 6.7‐fold difference in the maximal force between muscles, when normalized to a constant weight, that could be attributed to architectural features. Rations of wet weight to predicted maximal tetanic tension for each muscle and group were calculated to compare the relative priority of muscle force versus muscle length‐velocity for a given mass of muscle. These ratios varied from 0.4 to 4.84. The ratios suggest that velocity and/or displacement is a priority for the hamstrings, whereas force is a priority for the quadriceps and lower leg muscles. As much as a 12.6‐fold difference in maximal velocity between muscles can be attributed to differences in fiber lengths. This can be compared to approximately a 2.5‐fold difference in maximal velocity reported to occur as a result of biochemical (intrinsic) differences.
Ultrastructural aspects of mechano‐ and chemoreceptors in Branchiobdella pentodonta (annelida, oligochaeta)
Authors: Farnesi Rosalba M. , Marinelli Marinella , Tei Simonetta , Vagnetti Daniela 
Published: February 2005

AbstractThe surface receptors in Branchiobdella pentodonta consist of “sense buttons” prevalent on the prostomium, isolated sense cells all along the body of the animal, and free nerve endings. The “sense buttons” are uni‐ and multiciliated neurosensitive elements and supporting cells together with mucus glandular processes and muscle fibers. In the neurosensitive elements the cilia are always surrounded by cytoplasmic extroversion. The cytoplasm of the apical zone has abundant small dense granules, mitochondria, bands of tonofilaments, and microtubules. The cilium of uniciliated elements originates from three short roots. The highly vacuolated support cells surround the neurosensitive elements, separating them from each other. The “sense buttons” appear to be mechanoreceptors and chemoreceptors, and the isolated sense cells tactile mechanoreceptors, as are the free nerve endings. The surface receptors are compared with those of other Oligochaeta and Hirudinea.
Hemoglobin‐containing cells of Neodasys (Gastrotricha, Chaetonotida). I. Morphology and ultrastructure
Authors: Ruppert E. E. , Travis P. B. 
Published: February 2005

AbstractThe overall anatomy of Neodasys as well as data for hemoglobin‐containing cells are described. Hemoglobin‐containing cells are shown to be mesodermal specializations constituting approximately 14% of the animal's total body volume (4.87 ± 104 μl). These globular cells (10–14 μm) are situated in two longitudinal rows, each dorsolateral to the straight gut. Branches from the cells enwrap perikarya of muscle and nerve cells whose mitochondria are found just below their respective plasmalemmata in intimate association with the hemoglobin‐containing cells. The ground substance of the cytoplasm and nucleoplasm of these nearly organelle‐free cells is extremely electron‐dense and is presumed to represent the hemoglobin molecules. Locomotion analyses indicate that the cells can undergo a threefold change in linear dimension in 0.25 seconds, raising the possibility of convective mixing in these cells. Structural and ultrastructural comparisons with similar cells in adults of other species of Gastrotricha indicate that the hemoglobin‐containing cells of Neodasys may be homologous to the socalled Y cells of other species, some of which contain myofilaments. A muscle‐cell origin is considered for the evolution of hemoglobin‐containing cells of Neodasys.
Sensory surface of the saccule and lagena in the ears of ostariophysan fishes
Authors: Popper Arthur N. , Platt Christopher 
Published: February 2005

AbstractThe inner ears of a few fishes in the teleost superorder Ostariophysi are structurally unlike those of most other teleosts. Scanning electron microscopy was used to determine if other ostariophysans share these unusual features. Examined were the families Cyprinidae, Characidae, and Gymnotidae (all of the series Otophysi), and Chanidae (of the sister series Anotophysi), representing the four major ostariophysan lineages, the auditory organs of which have not yet been well described. Among the Otophysi, the saccular and lagenar otolith organs are similar to those reported for other ostariophysans. The lagena is generally the larger of the two organs. The saccular sensory epithelium (macula) contains long ciliary bundles on the sensory hair cells in the caudal region, and short bundles in the rostral region. The saccule and the lagena each have hair cells organized into two groups having opposing directional orientations. In contrast, Chanos, the anotophysan, has a saccular otolith larger than the lagenar otolith, and ciliary bundles that are more uniform in size over most of its saccular macula. Most strikingly, its saccular macula has hair cells organized into groups oriented in four directions instead of two, in a pattern very similar to that in many nonostariophysan teleosts. We suggest that the bi‐directional pattern seen consistently in the Otophysi is a derived development related to particular auditory capabilities of these species.
Metamorphic changes in the intestine of three species of lampreys
Authors: Hilliard R. W. , Bird D. J. , Potter I. C. 
Published: February 2005

AbstractMeasurements have been made of those changes which lead to increases in the surface area of the intestine during the metamorphosis of three species of lampreys. Although the intestine of the Southern Hemisphere lamprey, Geotria australis, increases in length by 1.13 times and in diameter by 1.12 times, the main factor influencing the 5.71 times increase in surface area is the development of longitudinal folds. The contribution of the typhlosole to the internal perimeter of the intestine is less in most life cycle stages of G. australis than in Lampetra spp. The changes in the various intestinal measurements of the nonparasitic species L. planeri parallel those of the presumed ancestral parasitic species, L. fluviatilis, during the first six stages of metamorphosis. However, the longitudinal folds, but not the typhlosole, subsequently start regressing in L. planeri just after the time when the rate of gonadal development increases markedly. An account is also given of the pattern of fold formation and the development of the typhlosolar vein in G. australis.
A fine structural study of metamorphosis of the hydrozoan Mitrocomella polydiademata
Authors: Martin Vicki , Chia Fu‐Shiang , Koss Ron 
Published: February 2005

AbstractThis report is a comprehensive fine structural analysis of the morphological changes occurring during metamorphosis of the marine hydrozoan Mitrocomella polydiademata. Five stages are recognized during metamorphosis: planulae just prior to settlement, ball and filiform stages, immature polyps, and primary feeding polyps. Settlement and metamorphosis of cnidarian planulae involve such changes as ciliary arrest, discharge of nematocytes, secretion of glandular cells, differentiation of cells, and changes in cell and body shape.
Embryonic development of the alimentary canal and ectodermal derivatives in the primitive moth,Neomicropteryx nipponensisissiki (Lepidoptera, Micropterygidae)
Authors: Kobayashi Yukimasa , Ando Hiroshi 
Published: February 2005

AbstractThe formation of the alimentary canal, nervous system, and of other ectodermal derivatives in the embryo of the primitive moth,Neomicropteryx nipponensisIssiki, is described. The stomodaeum is formed from an invagination in the medioposterior portion of the protocephalon. The proctodaeum arises as an extension of the amnioproctodaeal cavity. The midgut epithelium orginates from anterior and posterior rudiments in blind ends of the stomodaeum and proctodaeum. The decondary dorsal organ is formed in developing midgut. The development of the brain is typical of insects. The ventral nerve cord originates in large part from neuroblasts arising in 3 gnathal, 3 thoracic, and 11 abdominal segments. Intrasegmental median cord cells probably differentiate into both ganglion cells and glial elements of the ventral nerve cord; intersegmental cells appear not to participate in the formation of the nervous system. The stomatogastric nervous system develops from three evaginations in the dorsal wall of the stomodaeum, and consists of the frontal, hypocerebral, and ventricular ganglia, the recurrent nerve, and corpora cardiaca. Five stemmata arise from the epidermis on each side of the head. Five pairs of ectodermal invaginations are formed in the cephalognathal region to produce the tentorium, mandibular apodemes, corpora allata, and silk glands. Prothoracic glands orginate in the prothorax. Mesothoracic spiracles shift anteriorly to the prothorax during development. Oenocytes arise in the first seven abdominal segments. Invaginated pleuropodia are formed in the first abdominal segment.
The cocoon‐producing cells of Eisenia foetida (Annelida, Oligochaeta): A histochemical and ultrastructural study
Authors: Morris G. M. 
Published: February 2005

AbstractType 1 cells of the clitellar epithelium of Eisenia foetida secrete a protein resembling keratin in histochemical reaction. Ultrastructurally, type 1 cells are characterized by membrane‐bound, pockmarked granules ranging in diameter from 1.0 to 3.0 μm. Immature granules often exhibit an orgnized microfibrillar substructure. Individual microfibrils are 17 ± 1 nm in diameter. Type 2 cell secretion contains protein, nonsulfated acid mucosubstance, and neutral mucosubstance with 1,2‐glycol groups. The coarsely fibrillar granules are membrane bound and vary in diameter from 0.5 to 1.0 μm. The necks of both type 1 and type 2 cells contain a peripheral ring of microtubules, 20 ± 1 nm in diameter.
Size and shape of the mandibular condyle in primates
Authors: Smith Richard J. , Petersen Carl E. , Gipe David P. 
Published: February 2005

AbstractThe relationships between the size of the articular surface of the mandibular condyle and masticatory muscle size, tooth size, diet, and biomechanical variables associated with mastication were studied by taking 12 measurements on skulls of 253 adult female anthropoid primates, including three to ten specimens from each of 32 species.In regressions of condylar length, width, or area against body weight, logarithmic transformations substantially improve the fit of the equations compared with untransformed data. There is a strong relationship betwden condylar measurements and body weight, with all correlations being .94 or higher. The slopes of the allometric regressions of length, width, and area of the condylar head indicate slight positive allometry with body size.Folivorous primates have smaller condyles than frugivorous primates, and colobines have smaller condyles than cebids, cercopithecines, or hominoids. When colobines are eliminated, the differences between frugivores and folivores are not significant. However, the two species with the relatively largest condyles are Pongo pygmaeus and Cercocebus torquatus, suggesting that there may be a relationship between unusually large condylar dimensions and the ability to crak hard nuts between the teeth.Cranial features having strong positive correlations with condylar dimensions include facial prognathism, maxillary incisor size, maxillar postcanine area, mandibular ramus breadth, and temporal fossa area. These data are interpreted as indicating that relatively large condyles are associated with relatively large masticatory muscles, relatively inefficient mandibular biomechanics, and a large dentition. These relationships support the growing evidence that the temporomandibular joint is a stress‐bearing joint in normal function.
Skeletal muscle‐smooth muscle interaction: An unusual myoelastic system
Authors: Hikida Robert S. , Peterson Wesley J. 
Published: February 2005

AbstractThe serratus superficailis metapatagialis (SSM) of pigeons is a skeletal muscle with unusual properties. It lies between the ribs and the trailing edge of the wing, where it is attached to the skin by a system of smooth muscles having elastic tendons. Wing movements during flight induce marked changes in this muscle's length. The SSM inserts onto the deep fascia, and at its termination the skeletal muscle contains large numbers of microtubules. Many myofibrils attach to leptomeric organelles, which then attach to the terminal end of the skeletal muscle fiber. The deep fascia next connects to the dermis of the skin by bundles of smooth muscles that have elastic tendons at both ends. This system allows large movements of the muscle while preventing its fibers from overstretching. The movements and presumed forces acting at this muscle make the presence of sensory receptors such as muscle spindles unlikely. Spindles are absent in this muscle.
Functional and morphological bases of trophic specialization in sunfishes (Teleostei, centrarchidae)
Authors: Lauder George V. 
Published: February 2005

AbstractThe gross morphology and electrical activity of the muscles of the pharyngeal apparatus of centrarchid sunfishes (Lepomis) are analyzed within a monophyletic clade containing species specialized for snail‐eating. Outgroup comparisons of both structure and activity patterns of muscles permit examination of the relationship between specialized diet and function of the trophic apparatus. In most sunfish species, electrical activity in the pharyngocleithralis internus muscle significantly overlaps that in the retractor dorsalis muscle during pharyngeal transport, indicating that the upper and lower pharyngeal jaws retract together. Activity in the pharyngohyoideus, levatores externi, and levator posterior also significantly overlaps activity of the retractor dorsalis.Snail‐eating is associated with derived morphological, behavioral, and functional features. The shell is crushed before pharyngeal transport, correlated with extensive overlap in activity periods of muscles. One species, Lepomis microlophus, possesses a highly stereotyped neuromuscular repertoire that does not vary with prey type. All prey, even fish and worms, are subjected to crushing. Lepomis gibbosus exhibits the crushing pattern of muscle activity only when feeding on snails. L. microlophus has a hypertrophied levator posterior muscle, but the lines of action of the pharyngeal muscles are similar to the primitive condition. Pharyngeal transport in this species is unique in that activity of the pharyngocleithralis internus alternates with that of the retractor dorsalis.In sunfishes, alterations in the central control of peripheral structures have produced major changes in the sequence in which homologous components of the structural network are activated.
The exocrine glands of the male of Eldana saccharina walker (Lepidoptera, galleriinae): Intervention in precopulatory behavior
Authors: Farine Jean‐Pierre 
Published: February 2005

AbstractThe scent apparatus of male Eldana saccharina is a glandular complex on the costal area of the forewing. It consists of two parts; glandular complex 1 is composed of five kinds of cells (epidermal cells, scale cells, glandular cells, supporting cells, duct cells); glandular complex 2 also shows five types of cells (epidermal cells, scale cells, glandular cells, duct cells, trichogen cells). The secretory products of the two parts are discharged into separate ducts which converge before opening onto the lower side of the wing. The male also has two prominent hair‐pencils borne on the coremata and large secretory trichogen cells on the genital valves. Each of these exocrine gland components plays an important part in formation of the chemically complex pheromones utilized in the precopulatory behavior of the male.
The ultrastructure of the blood cells of the pike Esox lucius L.
Authors: Savage A. G. 
Published: February 2005

AbstractThe ultrastructure of pike peripheral blood cells, lymphocytes, thrombocytes, granulocytes, and monocytes is described. At present there are no reliable criteria for differentiating between round thrombocytes and small lymphocytes of fish on a routine basis. At the ultrastructural level thrombocytes could be clearly differentiated from lymphocytes by cytoplasmic canals and vesicles, marginal microtubules, and large glycogen deposits. Electron microscopic identification of thrombocytes was confirmed by examining the ultrastructural features of a purified thrombocyte fraction. In addition, a preliminary investigation of the structure of the haemopoietic cells in the thymus, anterior kidney, and spleen was carried out.
Developmental stages of ovarian follicles of the silkworm, Bombyx mori L
Authors: Yamauchi Hideo , Yoshitake Narumi 
Published: February 2005

AbstractOogenesis in the silkworm, Bombyx mori, was studied by light and electron microscopy of sections of resin‐embedded follicles. The development of the follicles was divided into a series of 12 distinctive stages based on various morphological criteria. Structural changes in the oocyte, nurse cells, and follicle cells are described and illustrated.
Freeze‐fracture characteristics of insect gustatory and olfactory sensilla. II. Cuticular features
Authors: van der Wolk Fran M. , Menco B. Ph. M. , Van Der Starre H. 
Published: February 2005

AbstractThe freeze‐fracture technique has been used to obtain detailed information about cuticular constituents and outgrowths of the external skeleton of labella and antennae in the bluebottle fly Calliphora vicina and the antennae of the small moth (Yponomeuta spp.). The lamellated exoskeleton has a fibrous endocuticle and an exocuticle lacking fibers. Ductuli connecting the inside of the animal with the outside run perpendicularly through the endocutile and at angles of up to 45° in the exocuticle. Skeletal outgrowths lack fibers and display fracture features similar to those of the exocuticle. Among those having neuronal endings, gustatory, olfactory, and tactile hairs can be recognized. Noninnervated outgrowths can be subdivided into scales and pseudotrichia. Criteria such as shape, length/width‐ratio of hairs, texture, presence and place of pores, shape of pores, and form of the socket or base are presented for further classification. Cuticular features of single‐walled olfactory hairs of Calliphora are compared with those of several other species. Based on the shape of the pores, five types of hairs can be distinguished using literature data. It is concluded that the freeze‐fracture technique is a valuable tool with which to describe the microarchitecture of the insect exoskeleton and supplements scanning electron microscopy, which is useful for describing the overall skeletal features.
The external morphology of contact‐chemoreceptive hairs of flies and the motility of the tips of these hairs
Authors: van der Wolk Fran M. , Koerten H. K. , van der Starre H. 
Published: February 2005

AbstractThe external morphology of contact‐chemoreceptive hairs (taste hairs) of six fly species, Calliphora vicina, Lucilia caesar, Musca domestica, Phormia terranovae, Sarcophaga carnaria and Stomoxys calcitrans, is described. The species can be distinguished by the differences between the patterns of taste hairs at the ventral side of their prothoracic tarsi. Taste hairs can be subdivided into morphological types, using the shape of the cuticle around the apical pore as criterion, even though this shape changes slightly on opening and closing of the pore. Light microscopical studies reveal that the nature and osmolarity of stimuli are decisive for the effect stimuli have on the shape of the top of the labellar hairs. The motions of the apical cuticle appear to be reversible.Gentle ultrasonic treatment preserves the shape of the cuticle of the top and the diameter of the pores on fluid stimulation. This technique makes it possible to study the effect of a previous stimulation on both tarsal and labellar hairs with the scanning electron microscope. It is supposed that stimuli can affect cuticular components around the pore, producing volume changes in that cuticle which alter the diameter of the pore.
Ultrastructure of the neuromuscular system of the polyp of Aurelia aurita L., 1758 (Cnidaria, scyphozoa)
Authors: Chia Fu‐Shiang , Amerongen Helen M. , Peteya Daniel J. 
Published: February 2005

AbstractFine structural study indicates that the neuromuscular system of stage I polyps of Aurelia aurita is exclusively ectodermal.The three major muscle fields are the radial muscles of the oral disc, the longitudinal muscles of the tentacles, and the muscle cords of the septae and the column; the muscle fields are in physical continuity at the peristomial pits and share a common innervation and type of myofibril. The myofibril is striated in the tentacle base, in the outer oral disc, and in the upper part of the muscle cord; it grades into a smooth muscle toward the tentacle tip, the mouth, and the lower part of the cord. There is a fourth field of longitudinal smooth muscle in the pharynx.The nervous system consists of an epithelial sensory cell in the tentacle and a single type of neuron found in the subepithelial layer of the tentacle, oral disc, and muscle cord. The lack of gap junctions suggests that there is no nonnervous conduction system. The subepithelial layer also contains three types of fibers and a type of soma which cannot be characterized as neuronal. The soma is identified as the “neurosecretory cell” described in Chrysaora. The absence of neuromuscular elements in the column and stolon distinguishes the Aurelia aurita collected from Washington, USA, from English polyps previously described.
The structure and function of the bursa copulatrix of the monarch butterfly (Danaus plexippus)
Authors: Rogers Steffen H. , Wells Harrington 
Published: February 2005

AbstractThe bursa compulatrix of the Monarch butterfly was investigated utilizing light microscopy, histochemistry, and scanning and transmission electron microscopy in order to relate its morphology to the release of sperm from the spermatophore. The bursa has a row of large chitinous teeth on either side of the organ. The dorsal and ventral surfaces are covered with chitinous plates, the plates having bristles on one side. A single layer of cells lies under both the plates and teeth, one columnar cell under each plate, one cuboidal cell under each tooth. The toothed area has no muscle cells. However, the dorsal and ventral hemispheres of the bursa each have a crescent‐shaped packet of muscle fibers that traverse the organ; there are no longitudinal fibers. Spermatophores with thick walls were found in the bursal lumen. Morphological evidence suggests that the presence of the spermatophores is sensed by the bristles and that the packets are opened by contraction of the muscles bringing the large teeth into contact with the spermatophore wall.