Anatomical Science International最新文献

This study aimed to discuss the clinical implications associated with the absence of the stapedius muscle and concomitant otosclerosis. The causes of mixed hearing loss are presented based on its embryonic development, audiological tests, and high-resolution computed tomography (CT) imaging. This case describes a 35-year-old female patient diagnosed due to bilateral conductive hearing loss. The patient complained of a significant deterioration of hearing and speech understanding lasting for several months. Preoperative audiometric work-up revealed air–bone gap with the presence of Carhart’s notch characteristic for otosclerosis. In CT scans otospongiotic focus was confirmed and the absence of stapedius muscle, its tendon, and pyramidal eminence was discovered. The patient underwent stapedotomy with good hearing result after healing. Understanding the stapedius muscle's development process is essential to comprehend the reason for its failure – the absence of the stapedius muscle results in exposure to acoustic trauma. Patients may experience hypersensitivity to sound, although it was not discovered in the described patient. High-resolution CT is a handy tool for analyzing congenital malformations of the middle ear. The absence of the stapedius muscle may also be indicated by other anatomical variations of the middle ear detected with high-resolution computed tomography images. The absence of the stapedius muscle may coexist with otosclerosis. Detailed in-depth analysis of high-resolution computed tomography images is the only tool to assess for stapes muscle defects without surgical intervention.

Satellite glial cells in the dorsal root ganglion are integral to the biology of sensory neurons. This review explores their unique fine structures, as well as their roles in pain signaling and neuronal differentiation. Satellite glial cells exhibit remarkable plasticity, including stem cell-like properties and the ability to influence neuronal morphology and function. Less-studied glial types, such as axonic satellite glial cells and newly identified glial populations, also offer insights into glial cell diversity and specialization. By focusing on the cellular and molecular mechanisms underlying satellite glial cell function, this review contributes to enhancing the foundational understanding of sensory system organization and glial biology.

Cadaveric surgical training (CST) can safely improve surgical skill. Recently, various innovations have made surgical training more realistic. Saturated salt solution (SSS) and urea methods are useful for plastic surgery training, because they better preserve the color and texture of soft tissues than formalin fixation (FA). Microvessels are invisible to the naked eye, and in this study, we visualized skin perforators by injecting dye into the flaps of nutrient vessels during hand and foot surgery. During each CST session, the instructor used three cadavers for demonstration. From 2017 to 2021, these cadavers were not stained, whereas from 2022 to 2023, the cadavers were stained to enhance the visualization of nutrient and perforating vessels. We compared the self-rated skill gains of participants who observed demonstrations on unstained cadavers from 2017 to 2021 and participants who observed demonstrations on stained cadavers from 2022 to 2023. Among 36 participants from the 2022–2023 group, 28 rated the staining of nutrient vessels and perforating branches as adequate. Of 32 participants, 29 preferred the use of dyed cadavers during training. Trainee skill increase for the digital artery flap, reverse digital artery flap, and dorsal metacarpal artery perforator flap was significantly higher in 2022–2023 (with stained cadavers) than in the earlier course without stained cadavers. SSS-fixed and urea-treated cadavers combined with vascular staining may be useful training models for flap elevation.

This case report presents an atypical transverse cervical artery with its detailed anatomy, morphogenesis, and association with the high arch-shaped subclavian artery. The atypical arteries, related arteries, and adjacent cervical and brachial plexuses were macroscopically examined in a 98-year-old Japanese female cadaver donated to The Nippon Dental University for medical education and research. The atypical deep branch of the transverse cervical artery originated from the internal thoracic artery and passed through between the C5 and C6 roots, in close contact with the C5 and C6 junction, to reach the dorsal side of the brachial plexus. The right subclavian artery exhibited a high arch-shaped coursing and traveled approximately 18 mm higher than the left subclavian artery. This atypical transverse cervical artery exhibits a combination of rare variations in its origin and course. The previous reports revealed that the transverse cervical artery arising from the proximal part of the subclavian artery tends to pass the lower part of the brachial plexus. However, this does not apply to the present case, implying that this atypical artery develops in a different manner from those previously described. Furthermore, the high arch-shaped subclavian artery in this case presumably arose by the suspension of the atypical transverse cervical artery at the C5 and C6 roots junction in a pulley-like structure. Clinicians performing pre- and intraoperative evaluations of neck surgery and catheterization of related arteries should consider that congenital anatomic variations in the transverse cervical artery may have cause anomalous subclavian artery coursing.

Tenomodulin (TNMD) is related to chondromodulin-1, a cartilage-derived growth regulator. It is specifically expressed in hypovascular connective tissues, including tendons and ligaments. Vascular endothelial growth factor A (VEGF-A) and calcitonin gene-related peptide (CGRP) correlate with angiogenesis and neurogenesis, respectively, during development. Because of that the morphological profiles of TNMD, VEGF-A, and CGRP distributions in developing diaphragm are still unclear, we aimed to determine the expression of mRNA and proteins of these 3 markers during the development of the central tendon of the diaphragm (CTD) and the surrounding diaphragm tissue in mice. Male mice from the embryonic and postnatal periods [embryonic day 14.5 (E14.5), E17.5, postnatal day 1 (P1), and P5] were used and their mRNA and protein expressions were assessed using in situ hybridization, immunohistochemistry and quantitative real-time polymerase chain reaction. The results showed that TNMD was preferentially detected in muscle–tendon junction of the CTD at E17.5 and P1, in contrast to scattered distribution of CGRP and VEGF-A throughout the diaphragm from E14.5 to P5. These findings may provide fundamental information concerning the role of the TNMD in the CTD development.

This study aimed to determine the normal size of the male external genital organs and anogenital distance in human fetuses during the fetal period through the anatomic morphometric method. The study was performed on 104 spontaneously aborted human male fetuses aged between 10 and 39 weeks of gestation. Fetuses were divided into groups according to gestational weeks, months, and trimesters. Parameters belonging to the male external genital organs were measured, including penile length and width, transverse scrotal diameter, anterior–posterior scrotal diameter, the distance from the anterior and posterior aspect of the penis to the center of the anus, and the anogenital distance. The mean of each parameter was computed by gestational weeks, months, and trimester groups, and data were presented as mean ± standard deviation. The mean of each parameter increased with gestational age, and statistically significant differences were observed between trimester groups. A high correlation was also determined between gestational age and the parameters measured.

The aim of this study was to define the branching patterns and innervation regions of the superficial branch of the radial nerve and the dorsal branch of the ulnar nerve and to evaluate the distance from 1–2, 3–4, 4–5, midcarpal radial, midcarpal ulnar, dorsal radioulnar joint, 6-radial, 6-ulnar dorsal arthroscopy portals to certain landmarks on the dorsal surface of the hand and wrist. Forty hands and wrists of 20 formalin-fixed intact cadavers without any known pathology, surgical scars or trauma were examined in the Macroscopy Laboratory of Ege University Faculty of Medicine, Department of Anatomy. Arthroscopy portals were placed using a dorsal approach to the wrist in the dissection method. In our study, the distances between the closest branch to the portal of the superficial branch of the radial nerve and the 1–2, 3–4, and midcarpal radial portals were 3.7 ± 2.0, 9.7 ± 3.8, and 8.0 ± 3.4 mm, respectively. And the distances between the closest branch to the portal of the dorsal branch of the ulnar nerve and the 4–5, 6-radial, 6-ulnar, and midcarpal ulnar portals were 18.3 ± 3.8, 7.1 ± 4.4, 2.5 ± 1.8, and 15.4 ± 4.4 mm, respectively. This study demonstrated that the results can guide surgeons in procedures such as the pin fixation of distal radius fractures, where surgeons may not always perform blunt dissection or expose nerves. The findings of the portal replacement would help any surgical procedure on the dorsal wrist be performed with caution.

The cerebral arterial circle morphologic variability has been extensively studied. The posterior cerebral artery (PCA) variants are rarely identified, except from the first segment (P1) hypoplasia or absence. Due to its unique morphology, the computed tomography angiography (CTA) of a 34-year-old female patient was further investigated. On the right side, the typical PCA originated as the terminal branch of the basilar artery. An accessory PCA was also identified originating from the right internal carotid artery (ICA), while the right posterior communicating artery was absent. This variant corresponds to the “complete” duplication of the PCA. The left-sided PCA originated from the ICA, while the P1 was hypoplastic, representing the “partial fetal-type PCA.” The rest of the cerebral arterial circle was typical. The present case of PCA “complete” duplication corresponds to a scarce variant, with a reported prevalence of 0.04%, while the fetal-type PCA is the most commonly observed variant.

The human upper limb has undergone various evolutionary myologic changes, accompanied by corresponding modifications in the anatomical course of neurovascular structures. In this study, we aimed to elucidate the emergence of the accessory head of the flexor pollicis longus (AHFPL) muscle as a beneficial biomechanical evolutionary development and its topographical relationship with adjacent neurovascular structures. In this pursuit to understand this phenomenon, dissections were conducted on sixty-two upper limbs from thirty-one cadavers. We found a strong positive correlation between the length of the AHFPL and the distance of the branching point of the brachial artery, ulnar artery, and median nerve into the anterior interosseous nerve. Additionally, we noted a significant negative correlation between the width of the AHFPL muscle and the angle formed between the long axes of the FPL and AHFPL. This increases the angle between the resultant vector and the FPL muscle, decreasing the angle between the AHFPL and the resultant force. Consequently, the resulting force shifts from the initial radial position to a slightly ulnar side, balancing the muscle forces at the same point. The authors hypothesize that this resultant vector provides a biomechanical advantage for the thumb, enhancing emphatic grip precision, providing extra power, and enabling meticulous cupping grip when using tools. Rather than considering the presence of AHFPL as a mere anatomical variation, it should be viewed as an advantageous evolutionary biomechanical development.