Journal of Anatomy最新文献

{"title":"Characterisation of spinal ligaments in the embryonic chick.","authors":"Sarah Hennigan, Ebru Talak Basturkmen, Rebecca A Rolfe","doi":"10.1111/joa.70006","DOIUrl":"https://doi.org/10.1111/joa.70006","url":null,"abstract":"<p><p>Ligaments are important connective tissues within the musculoskeletal system that connect bone to bone and provide support and stability. The spine contains a number of ligaments that predominantly function in mechanical stabilisation and allow for certain ranges of spinal motion. Establishment of mechanical stability provided by spinal ligaments has not been described, and it is not known to what extent failure or inadequate spinal ligaments contribute to spinal conditions, such as scoliosis. While there are many similarities between ligaments and tendons, there is no experimental evidence investigating the development of these stability-bearing tissues. This study uses the embryonic chick model Gallus gallus and investigates the development of spinal ligaments in the thoracic spine, examining structure and molecular expression across development. Findings show organisational changes in spinal ligaments in association with vertebral shape changes from cranial to caudal, with the anatomical identification of six vertebral ligaments in the thoracic spine. As development proceeds, the size of the anterior longitudinal ligament, on the ventral surface of the vertebral body, and the supraspinous ligament, on the dorsal side of the spine, becomes greater, with the orientation of collagen fibres in the supraspinous ligament becoming more aligned. In addition, this study demonstrates that cell density decreases and nuclei become smaller and more circular across development. This study provides evidence that the embryonic chick is an appropriate model to study spinal ligament development and has added knowledge on the structural hallmarks of embryonic vertebral ligament tissues. These findings allow for subsequent investigation of the mechanical and molecular characteristics of spinal ligament development, for example useful for determining if in utero movement is important for the establishment of spinal ligament stability. Use of this model and integration of findings with additional models will provide knowledge of the contribution of spinal ligaments in spinal failure conditions.</p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversity and development of the hemibacula of croaking geckos (Sphaerodactylidae: Aristelliger).","authors":"Aaron H Griffing, Daniel J Paluh, Jonathan C DeBoer, Juan D Daza, Tony Gamble, Anthony P Russell, Aaron M Bauer","doi":"10.1111/joa.70009","DOIUrl":"https://doi.org/10.1111/joa.70009","url":null,"abstract":"<p><p>Among squamates, hemipenes are known to evolve rapidly and exhibit diverse shapes, sizes, and ornamentation. Croaking geckos (Aristelliger) are unique among geckos in exhibiting mineralized structures (hemibacula) in their hemipenes. We here describe the gross morphology of the hemibacula of each currently recognized species of Aristelliger, document hemibacular histology, and report on hemibaculum development. We confirm the presence of hemibacula in all currently recognized species and demonstrate that three distinct morphologies correspond to three putative clades in the genus. Histology revealed that hemibacula are superficially similar to chondroid bone and composed of mineralized dense connective tissue covered in a thin layer of epidermis with alcian-positive cells embedded within a mineralized matrix. Additionally, we demonstrate that hemibacula do not develop until past the onset of sexual maturity and that hemibaculum length scales isometrically with body size. We hypothesize that hemibacula of Aristelliger develop via peramorphosis, a phenomenon also expressed in the cranial morphology of this genus. Additionally, we speculate on the functional significance of these enigmatic structures.</p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Osteology and arthrology of the ankle and tarsometatarsus of anoles (Iguania: Anolidae): not convergent with geckos but divergent from the ancestral iguanian condition.","authors":"Anthony P Russell, Lisa D McGregor, Timothy E Higham","doi":"10.1111/joa.70007","DOIUrl":"https://doi.org/10.1111/joa.70007","url":null,"abstract":"<p><p>The ankle joint of lizards has a complex structure, and its features help to define the Lacertilia. The configuration of this joint in its ancestral state entrains conjoint flexion-extension and long-axis rotation of the pes relative to the long axis of the crus. In Gekko gecko these actions can be decoupled because of derived features of the ankle joint. The increased degrees of freedom of the motions of the pes are associated with the operation of the adhesive toe pads carried on the digits. Among iguanian lizards, the genus Anolis has independently acquired a digital adhesive system that employs toe pads. Geckos and anoles are thus regarded as being convergent in the possession of a digital adhesive apparatus. This raises the question of whether anoles exhibit a similar ankle structure to that of geckos to allow them to deploy their toe pads in a mechanically similar fashion. Comparative analysis reveals that this is not the case, and that Anolis retains an ankle structure very similar to that of its iguanian relatives and non-gekkotan lizards in general. Some differences set its ankle and foot structure apart from those of its closest relatives, but these exaggerate the differences between geckos and anoles rather than lessen them: its ankle joint architecture is more sharply contoured than that of its close iguanian relatives; the ventral peg on the fourth distal tarsal is more extensive; its metatarsals are more gracile in form, relatively longer, and their distal joints are all unicondylar; its fifth metatarsal has a longer shaft and a less prominently sculpted ventral surface; and the meniscus that intervenes between the anterodistal extremity of the astragalocalcaneum and the more medial of the metatarsals is more extensive. These attributes combine to limit degrees of freedom at the ankle joint but provide the digits with greater mobility relative to the metatarsals. Such derived features may prove to be associated with enhanced capabilities for grasping narrow perches, sprinting and jumping, activities common to anoles but much less evident for geckos. The ways in which geckos and anoles negotiate their locomotor environments may be associated with the differences evident in their ankle and tarsometatarsus structure-anoles seemingly using the combination of their toe pads and claws to navigate along and between relatively narrow branches and geckos using broader, more expansive sectors of the substratum. Anoles and geckos have incorporated adhesive toe pads into their locomotor apparatus from structurally different starting points, with the former integrating the adhesive system into a pedal configuration that departs little from the ancestral lacertilian pattern. Beyond the possession of toe pads the pedal structure of anoles exhibits little in the way of convergence with that of geckos.</p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Embryologıcal development and comparatıve analysıs of Anguis colchica (Nordmann, 1840): Insights into ossification and morphologıcal traits in anguimorph lizards.","authors":"Elif Yıldırım Caynak, Eda Şen, Çetin Ilgaz, Yusuf Kumlutaş, Ahmet Gökay Korkmaz, Kamil Candan","doi":"10.1111/joa.70002","DOIUrl":"https://doi.org/10.1111/joa.70002","url":null,"abstract":"<p><p>Embryological studies on squamates, dating back to the 19th century, remain limited, particularly concerning species within the anguimorph clade, a group of lizards with distinct morphological traits. In this study, we document the embryological development of Anguis colchica through three stages and provide a comparative analysis with other anguimorph species. Morphological features, including eye formation, pharyngeal arch development, fusion of facial primordia, limb morphogenesis, pigmentation, and scale differentiation characterized developmental stages. The development of A. colchica was analyzed across three embryonic stages, with adult skeletal structures also assessed and compared to those of other anguimorphs. Our findings indicate that ossification in A. colchica begins before stage 6, marked by the emergence of cranial skeletal elements such as the premaxilla, maxilla, nasal, prefrontal, parietal, squamosal, quadrate, mandible, postorbital, and postfrontal bones. At stage 7, the medial regions of the frontal and parietal bones remain unfused. Understanding whether skull and skeletal structure variations influence ossification patterns in anguimorphs is crucial. Comparative analysis of developmental sequences across different anguimorph species reveals significant similarities in their embryological progression.</p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The cochlear apex demystified: Implications from synchrotron radiation phase-contrast imaging and microscopy for cochlear implantation.","authors":"Hao Li, Rudolf Glueckert, Anneliese Schrott-Fischer, Karin Staxäng, Hanif M Ladak, Helge Rask-Andersen, Sumit Agrawal","doi":"10.1111/joa.70001","DOIUrl":"https://doi.org/10.1111/joa.70001","url":null,"abstract":"<p><p>Due to the complex organization of the human cochlear apex, further analysis of the tonotopic relationship between the organ of Corti (OC) and spiral ganglion (SG) is required in relation to cochlear implantation. In this study, the human SG nerve fiber organization and ultrastructure were assessed using semi-thin light microscopy sectioning and three-dimensional (3D) synchrotron radiation phase-contrast imaging (SR-PCI). A fresh human temporal bone underwent high-resolution SR-PCI with a dual-detector system. Orthogonal sectioning, cropping, and tissue segmentation were used to create high-resolution 3D reconstructions. Peripheral dendrites were traced from the basilar membrane to the SG, and a tonotopic map was constructed using Greenwood's function. Results were compared and validated against novel high-resolution microscopy data of a sectioned human cochlea. Only the basal and initial middle turn of the cochlea displayed a well-defined Rosenthal's canal (RC), and after 450 degrees, this converged into a central modiolar space. The OC and SG tonotopic maps remained closely aligned for angular depths up to approximately 650 degrees, after which the SG frequencies became significantly more spatially compact relative to the OC. In the central modiolus, the apical 1.37 mm of the SG contained over four octaves of tonotopic representation. In comparison, the compressed apical SG represented 9.6 mm of the OC (28% of the overall length) over the same tonotopic range. These results were validated with microscopy, which revealed that this apical SG contained around 8000 neurons and represented 960 inner hair cells along the OC. This is the first study to present the detailed cellular organization and 3D tonotopic arrangement of the human SG within the central modiolus. For low frequency stimulation, rate-based coding may be required to augment tonotopic mapping in the compressed SG regions. In addition, the OC tonotopic map has significantly less compression and could potentially be targeted directly for place-based coding.</p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144284455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Issue Cover (July 2025)","authors":"","doi":"10.1111/joa.70004","DOIUrl":"https://doi.org/10.1111/joa.70004","url":null,"abstract":"<p>Cover image: ‘A deep dive into the leg musculature of the Antarctic Emperor penguin <i>Aptenodytes forsteri</i> across different ontogenetic stages.’ See M.A. Sosa and C. Acosta Hospitaleche, ‘Hindlimb muscles of the Emperor Penguin <i>Aptenodytes forsteri</i> (Aves, Sphenisciformes) at different postnatal ontogenetic stages’, this issue.</p><p>\u0000 \u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":"247 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/joa.70004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144264518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determining modulus of elasticity using finite element analysis and non-destructive testing: Are aquatic animal whiskers stiffer?","authors":"Robyn A Grant, Charlotte Brassey, Victor G Goss, Eugene L Starostin, Tom Allen","doi":"10.1111/joa.14289","DOIUrl":"https://doi.org/10.1111/joa.14289","url":null,"abstract":"<p><p>Approximating the stiffness of biological materials can give important insights into how structures deform and when they may fail. Some samples may be too precious to test to destruction, or too fine to position accurately for conventional material testing, which makes it challenging to obtain approximations of material stiffness. Using two-dimensional scans, non-destructive bending tests, and finite element (FE) modeling, we show that we can approximate the modulus of elasticity of samples by fitting FE model data to that of experimental bend tests. We demonstrate our protocol on representative whiskers from three species of Carnivorans, including a terrestrial red fox, semi-aquatic Eurasian otter, and aquatic phocid grey seal. Grey seal whiskers had the highest approximated modulus of elasticity (0.5-19 GPa), followed by Eurasian otter (0.5-13 GPa) and red fox (0.1-1.5 GPa). We suggest that, as in many other biological structures, adaptations in both the shape and material stiffness of the whisker contribute to how it bends when loaded. Specifically, a larger base radius and higher material stiffness both act to increase whisker flexural rigidity in the aquatic grey seal. This protocol has broad applications in comparative biology and provides a way to determine shape and material stiffness information for various flexible specimen types.</p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The secret in their eyes: A review of the recessus orbitalis, a unique structure of flatfishes.","authors":"Paulo Presti, G David Johnson, Aléssio Datovo","doi":"10.1111/joa.70000","DOIUrl":"https://doi.org/10.1111/joa.70000","url":null,"abstract":"<p><p>Flatfishes (Pleuronectiformes) are famous for having one of the most peculiar anatomical transformations in the animal kingdom, the ontogenetic migration of one eye from one side of the head to the other. But the eyes of flatfishes also carry a much lesser known but equally unique modification: an organ called the recessus orbitalis, which is responsible for projecting the eyeball above the level of the head, thus expanding their fields of vision. However, the morphology and distribution of the organ have never been thoroughly investigated. Previous studies reported only part of the recessus orbitalis and mistakenly suggested that it opened into the orbital cavity. We show that the organ forms a fully enclosed system consisting of two interconnected chambers: the facial chamber, which corresponds to the organ previously reported in the literature, and the scleral chamber, which encases the inner portions of the eyeball and is more challenging to detect through manual dissection. The organ is filled with interstitial fluid, and the walls of both chambers-especially the facial one-contain smooth, not skeletal and muscle fibers. These findings combined with field observations allowed us to propose a new functional model for the recessus orbitalis. The organ seems to operate as a dual-pump system, dynamically shifting interstitial fluid between the facial and scleral chambers. Inflation of the facial chamber results in eye retraction, whereas inflation of the scleral chamber causes eye protrusion. The presence of smooth muscle fibers, which can sustain contractions with minimal energy expenditure, supports this inferred mechanism, allowing the eye to remain fully protruded or retracted for extended periods. The recessus orbitalis has never been confirmed in several flatfish families, and the organ was recently considered absent in Psettodidae, the sister group to all other flatfishes. However, we positively identified this organ in all 74 species examined representing all 16 currently recognized flatfish families, including Psettodidae. This indicates that the presence of the recessus orbitalis is an evolutionary novelty (synapomorphy) for the entire Pleuronectiformes.</p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144234189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data-driven standards for infant skull thickness distributions in computational modeling and analysis.","authors":"Yousef Alsanea, Tagrid M Ruiz-Maldonado, Brittany Coats","doi":"10.1111/joa.14287","DOIUrl":"https://doi.org/10.1111/joa.14287","url":null,"abstract":"<p><p>Child abuse remains a global issue, with infants under 1 year of age facing the highest risk of fatality and recurrence if abuse is not detected. Computational modeling is a powerful tool for predicting injury from real-world trauma, offering a means to validate caretaker-reported histories and prevent further abuse. A key challenge and gap, however, lies in capturing the natural anatomical variability within a population to enhance injury prediction accuracy. This study addresses this gap by quantifying skull thickness distributions in a robust sample (n = 266) and establishing data-driven anatomical standards based on similarities in thickness patterns. The study examined age and head circumference as predictors of skull thickness growth. For infants younger than 2.5 months, head circumference was a more reliable predictor than age. Infants under 12 months old were categorized into four age groups-0-1.5, 1.5-5.9, 5.9-10.2, and 10.2-12 months-using natural thickness distribution breaks and a variance optimization routine. No significant sex differences were found in average skull thickness within each cranial bone (left and right parietal, frontal, and occipital), but there were 53 locations with significant sex differences at various stages of development. Symmetry tests suggested that lateral symmetry may be an appropriate assumption for infants under 12 months. Representative thickness distributions for each age group were selected based on similarity scores. This study is the first to apply data-driven methods to categorize infant skull thickness distributions, generating essential guidelines for age- and sex-based models in predicting injury from head trauma in infants.</p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144208554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-dimensional analysis of seminiferous tubules and spermatogenesis in the musk shrew, Suncus murinus.","authors":"Hiroki Nakata, Mahiro Yamaguchi, Takuya Omotehara, Koichiro Ichimura, Shuang-Qin Yi, Shoichi Iseki","doi":"10.1111/joa.14288","DOIUrl":"https://doi.org/10.1111/joa.14288","url":null,"abstract":"<p><p>We reconstructed in three dimensions all seminiferous tubules in the testes of 1- and 8-week-old musk shrews (Suncus murinus), a small experimental mammal belonging to the family Soricidae, order Eulipotyphla that preserves the primitive characteristics of mammalian species. Quantitative analyses revealed that the basic structure of seminiferous tubules at 1 week postpartum remained consistent into adulthood. A single dominant seminiferous tubule with extensive branching accounted for more than 90% of the length of all tubules, a feature distinct from that in mice and rats. Pachytene spermatocytes were observed in the seminiferous epithelia of most tubules at 1 week, which was markedly earlier than in mice and rats. At 8 weeks, a mosaic pattern of active and inactive areas of spermatogenesis was observed through the length of seminiferous tubules, a feature distinct from that in mice and rats. The percentage of active areas was significantly lower in tubule portions near the rete testis. The unique characteristics of seminiferous tubules in the musk shrew will provide a basis for investigating not only the phylogeny of testis functions but also the regulation of spermatogenesis and possibly the pathogenesis of azoospermia.</p>","PeriodicalId":14971,"journal":{"name":"Journal of Anatomy","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144208555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}