Anatomy & Cell Biology最新文献

Trepanation has been reported on skulls from major ancient civilizations since the Neolithic period. In this study, on a skull excavated from the Qau village site during the Old Kingdom period of ancient Egypt (7th to 8th dynasties; 2181-2160 BCE), we found a highly probable sign of therapeutic trepanation in the frontal bone. The practice of trepanation was suggested by the healing sign observed at the site on the frontal bone of case QAU-26. Based on our radiological findings, we presume that this ancient Egyptian male likely suffered from frontal sinus pathology, which may have led to the accumulation of exudates inside the cavity. To alleviate the symptoms of sinusitis, the ancient practitioner may have attempted to induce drainage of exudates from the left frontal sinus by therapeutic trepanation. Our findings are significant in medical history, considering that, thus far, trepanation has been reported rarely in ancient Egyptian civilization. This is also the first reported case of trepanation presumed to have been performed to alleviate paranasal sinusitis, which is of paleopathological and clinical significance.

The growing use of injectable cosmetic fillers has been accompanied by an increase in reports of acute vision loss, typically caused by inadvertent intravascular injection and subsequent embolization of the ophthalmic artery, resulting in ocular ischemia. Effective management of this complication remains challenging, as clear clinical guidelines for retrobulbar hyaluronidase injection are lacking. This ultrasound-based observational anatomical guideline provides practical recommendations for retrobulbar administration of hyaluronidase. Real-time ultrasonography allows for direct visualisation of orbital anatomy, enabling the injector to identify the optic nerve sheath complex and surrounding vascular structures. The central retinal artery's entry point into the optic canal is a key anatomical landmark for directing treatment. Based on ultrasound observations, the inferolateral quadrant of the orbit is identified as the safest and most accessible entry site, reducing the risk of damage to extraocular muscles, cranial nerves, and major vessels. The use of ultrasonography enhances both precision and safety, supporting timely and effective management of filler-related ocular complications. Ultrasound observation further confirms that the inferolateral orbital approach offers the most reliable and safe access for retrobulbar hyaluronidase injection. The superior orbital rim and close proximity of the globe restrict needle trajectory from above, increasing the risk of ocular injury. In contrast, the inferior approach provides a wider anatomical corridor, reduces the likelihood of direct contact with the eyeball, and allows safer navigation around critical neurovascular structures. Incorporating real-time ultrasound enhances precision, making the inferior approach the preferred route for managing filler-related ocular complications.

The external granular layer (EGL) is a transient yet crucial layer for the formation of cerebellar cortex. Genetic mechanisms, including the sonic hedgehog (SHH) pathway is key to the proliferation of granule cell progenitors (GCPs), and disruptions in this process can lead to cerebellar disorders like medulloblastoma and Dandy-Walker malformation (DWM). The review consolidates findings from studies on human cerebellar development, primarily focusing on neurogenesis, the role of genetic pathways in EGL regulation, and its involvement in congenital disorders. In total 42 articles were comprehensively reviewed and the research gaps in current research on human foetal cerebellum development was highlighted. The key findings from various sections of the review are summarized as follows. In terms of gestational development, the timeline for the appearance and regression of the EGL in humans remains imprecise. Regarding morphometry, the EGL thickness shows a marked increase between 16 and 28 gestational weeks, reaching an average peak of approximately 50.05 μm around 24th to 28th weeks, and then declines during the late third trimester. In the context of gene expression, SHH signalling plays a critical role in driving the proliferation of GCPs within the EGL. When considering congenital disorders, disruptions in EGL development are associated with conditions such as medulloblastomas, DWM, and pilocytic astrocytoma. The review highlights major research gaps and underscores the need for further human-specific studies to enhance understanding and guide therapies for cerebellar disorders.

The orbital tubercle, also known as Whitnall's tubercle, was first described by S.E. Whitnall in 1911 and is a significant anatomical landmark on the zygomatic bone that serves various structural and clinical functions. Understanding its anatomy is essential for protecting adjacent soft tissues during surgical procedures and its role in forensic studies. This study aims to assess the prevalence, precise location, and morphological characteristics of Whitnall's tubercle in adult human skulls. A cross-sectional observational study was conducted on 108 orbital fossae of 54 well-preserved adult human skulls. Whitnall's tubercle was classified as apparent if visible or non-apparent if detectable only by palpation. Its dimensions and distances from nearby anatomical landmarks were measured. Statistical analyses were performed to compare measurements between sides. Whitnall's tubercle was present in 106 (98.1%) out of 108 examined orbital fossae, with 67 classified as apparent and 39 as non-apparent. The mean longitudinal length was 6.59±0.99 mm on the right and 6.86±1.30 mm on the left (P=0.025), while the transverse lengths showed no significant difference (P=0.63). The majority of Whitnall's tubercle presented an oval shape (92.5%), with no significant difference between sides (P=0.63). The distances between Whitnall's tubercle and selected anatomical landmarks showed minor variations, but none reached statistical significance. This study provides valuable insights into the anatomical characteristics of Whitnall's tubercle, emphasizing its clinical relevance in orbital surgery and forensic applications. Understanding these features can enhance surgical precision and improve patient outcomes.

Although human lymph node architecture varies by site, the intranodal distribution of interdigitating dendritic cells (DCs) remains poorly understood. To address this, we compared the morphology of submandibular, paratracheal, mesenteric, and inguinal nodes obtained from 24 donated cadavers. Immunoreactivity was evaluated by comparing these cadaveric nodes with surgically resected lymph nodes obtained from five old-aged patients with nonmetastatic cancer. Despite the limited number of dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN)-positive cells (candidate DCs) in cadaveric specimens, these tissues were deemed suitable for analysis. The submandibular and paratracheal nodes exhibited a belt-like cortex, with paracortical lymph sinus extending from the subcapsular sinus and surrounding the follicle. In contrast, the mesenteric and inguinal nodes contained multiple island-like cortices separated by thick paracortical lymph sinuses. Endothelial cells lining all lymph sinuses showed reactivity for smooth muscle actin and DC-SIGN. Macrophages and candidate DCs were abundant in the paratracheal and mesenteric node sinuses but scarce in the submandibular and inguinal nodes. Notably, the medullary sinus in the submandibular and inguinal nodes was filled with fibrous tissue, and the surrounding paracortical sinuses formed a "sea" around the island-like cortices, often resulting in loss of nodal polarization. Although the proportional area occupied by candidate DCs per nodal section was almost the same at the four sites, the overlap between DCs and macrophage clusters was small in paratracheal and inguinal nodes. The amount of afferent lymph and the retention of efferent lymph might determine the site-dependent architecture. Therefore, in aged nodes, DCs were preferentially localized in the paracortical sinus.

The occipital bone squamosa (OCS) is unique because of its double origin from both endochondral and membranous bones. The present study attempted to demonstrate the process of connection between these two bone types. We examined sagittal and frontal histological sections from 29 human fetuses with a crown-rump length ranging from 38 to 328 mm (approximately 7-39 weeks of gestational age [GA]). An initial cartilage plate appeared in the posterior side of the fourth ventricle at GA 7-8 weeks and extended inferiorly to connect with the cartilaginous basioccipital and condyle. At GA 9-10 weeks, on the superior side of the cartilage plate, membranous bone fragments appeared and adopted an arrangement resembling a chain of irregularly-shaped beads. They did not form a complete plate-like bone until late-term. At GA 11-12 weeks, endochondral ossification centers appeared at the upper and lower ends of the cartilage plate. At GA 12-15 weeks, a bar-like periosteal bone developed near and superior to the upper ossification center. Notably, sinusoidal structures, which were surrounded by growing periosteal bones, contained island-like clusters of calcified cartilage fragments. Therefore, the upper ossification center appeared likely to "migrate" downward and become distant from membranous bones. The extending periosteal bone reached and joined the membranous bone fragments. Consequently, the periosteal bones connected between the endochondral and membranous bones in the OCS. This connection was quite different from the other components of the calvaria, where membranous bones overlap the skull base cartilages at the margin.

The sella turcica, part of the sphenoid bone located at the base of the skull, is associated with multiple important neurovascular structures. Hence, a detailed knowledge of its variations is critical to clinicians who interpret imaging or surgeons who operate in this region. Our aim was to better understand the pathology of osteophytosis, often found related to the sella turcica. The study sample (n=1,083, human skulls) was obtained from the skeleton collection housed in the Natural History Museum, Cleveland, OH, USA. All skulls were assessed for osteophytes in the sella turcica region (defined as an overgrowth of 1 mm or more). Morphometrical measurements included skull length, width, and thickness, correlated to seller osteophytes. Cranial shape was related to the presence of osteophytes. Greater prevalence was seen in the brachycephalic skulls, with a significantly higher ratio of presence in older people (79.6%) compared to a younger population (26.4%); greater prevalence was also observed in female skulls with a composite thickness of the frontal, parietal and occipital bones. A multifactorial analysis using a logistic regression model defined a statistically significant model, by explaining 37.0% of the variance in osteophyte presence and correctly classifying 77.2% of the cases. Female skulls were 1.76 times more likely to display osteophytes of the sella turcica. Increasing age and increased skull thickness were associated with an enhanced likelihood of exhibiting osteophytes involving the sella turcica, thereby, the shape of the skull, age, and sex partially explain the variations observed for the presence of sella turcica osteophytes.

As dental schools increasingly share anatomy curricula with medical programs, a growing mismatch is emerging between what dental students need and receive. While head and neck anatomy is essential for all health professionals, dental students require significantly more detailed, region-specific anatomical knowledge, especially regarding the oral cavity, neurovascular structures, and surgical landmarks. Yet, this level of instruction is often delivered by medical school faculty unfamiliar with the unique clinical demands of dentistry. This commentary highlights the limitations of the "borrowed" faculty model and argues for dedicated, dental-aware anatomy educators actively engaged in anatomical research to ensure competent, confident clinical performance by future dentists.

The iliocapsularis muscle (ICM), a small and often overlooked muscle of the anterior hip, has recently gained attention for its potential clinical and surgical relevance. Despite being anatomically distinct and commonly present, the ICM remains underappreciated among clinicians and anatomists. This narrative review aims to synthesize recent anatomical and clinical literature on the ICM, focusing on its origin, insertion, innervation, vascular supply, anatomical variations, histological features, and functional significance. The ICM originates from the anteromedial hip capsule and the anterior inferior iliac spine, typically inserting distal to the lesser trochanter. Its proposed function includes tightening the anterior hip capsule and stabilizing the femoral head. Electromyographic studies suggest that the ICM plays an active role during hip flexion and dynamic gait phases. Anatomical variations, including variant origins and insertions, have been documented, along with unique innervation and fascial compartmentalization. Clinically, the ICM serves as a useful landmark in total hip arthroplasty and periacetabular osteotomies. Its hypertrophy or atrophy has been linked to hip pathologies such as acetabular dysplasia and femoroacetabular impingement. Imaging modalities, including ultrasound and elastography, have further supported its diagnostic utility. This review emphasizes the need for greater recognition of the ICM's structure and function, underscoring its relevance in orthopedic procedures and hip pathology diagnostics.

The omohyoid is a digastric muscle that crosses the neck from the superior border of the scapula to the body of the hyoid bone. Variations in the omohyoid muscle are common, but a double omohyoid is considered rare and may have important clinical implications. The anatomical dissection of the neck of a middle-aged male cadaver revealed an abnormal three-headed duplicated omohyoid muscle. Behind the clavicle, the intermediate head bifurcated and fused with the medial and lateral heads, forming a small plexus that gave rise to two separate bellies, one lateral, and one medial. The bellies ascended in a superomedial direction before inserting into the hyoid bone next to each other. The intermediate tendon was rudimentary in the lateral belly and absent in the medial one. The anatomical variation described here has not been previously reported and may have clinical significance.