Microanatomy Research Articles

Microscopic Anatomy of Orbital Septum.

To study the microscopic anatomy of the orbital septum and evaluate its relationships with the adjoined structures. Histological evaluation of 11 upper eyelids (5 right, 6 left) from 10 Japanese cadavers (age range: 36-94-year-old, average: 71.1) was performed. The specimens were fixed in 10% formalin and stained with Elastica Van Gieson. Specimens were microscopically analyzed using different magnifications (20×, 40×, and 100×). The orbital septum was the single fibrous layer in all the specimens, anteriorly separated from the retro-orbicularis fat pad capsule and posteriorly from the preaponeurotic fat pad capsule. At the junction of the orbital septum with the levator aponeurosis, the orbital septum proceeded towards the tarsal plate, and the preaponeurotic fat pad capsule reflected posteriorly. The orbital septum is constituted of a single layer of fibrous tissue anteriorly separated from the retro-orbicularis fat pad capsule and posteriorly from the preaponeurotic fat pad capsule by the corresponding virtual spaces.

Male reproductive system of the deep-sea acorn worm Quatuoralisia malakhovi (Hemichordata, Enteropneusta, Torquaratoridae) from the Bering Sea

BackgroundThe deep-sea acorn worm Quatuoralisia malakhovi belongs to the phylum Hemichordata, class Enteropneusta, family Torquaratoridae, which was described in 2005. Owing to their epibenthic lifestyle and deep-sea habitat features, torquaratorids differ anatomically from shallow-water acorn worms; however, their morphology and fine structure are poorly studied. We have the opportunity to make three complete detailed series of histological sections of Q. malakhovi and to study the microscopic anatomy, histology and fine structure of the reproductive system of this acorn worm using scanning and transmission electron microscopy.ResultsThe sexes of Q. malakhovi are separate and indistinguishable externally. The lobed testes occupy the dorsal side of the genital wings and distinctly bulge into the peribranchial cavity by their mature lobes. The central part of the testis is always submerged into the genital wing and opens via a single gonad pore. The monociliary muscle cells stretch along the external wall of the testis and surround the gonad pore, probably taking part in the contraction of the testis lobes for spawning. The germinative epithelium of the testis contains spermatogenic cells at different stages of development and interstitial cells. Yolk cells are not found. Interstitial cells embrace the spermatogonia and spermatogenic columns, providing horizontal compartmentalization of the germinative epithelium, and contain numerous phagosomes with remnants of degenerating spermatogenic cells. The testis wall contains haemal lacunae, which are usually located on the side opposite the gonad pore. We describe the fine structure of spermatogonia, spermatocytes clustered in spermatogenic columns, spermatids, and spermatozoa. Spermatozoa are of the ectaquasperm type and consist of an acorn-shaped head and a flagellum 18–25 µm long. The sperm head includes a beak-shaped acrosomal part, a spherical nucleus and a midpiece containing a ring of 5 or rarely 6 mitochondria.ConclusionsThe male reproductive system and sperm structure of Q. malakhovi, a representative of the family Torquaratoridae, have a number of differences from shallow-water acorn worms; however, the spermatogenesis and sperm structure of Q. malakhovi generally follow the pattern of the other three enteropneust families, and the phylogenetic significance of these deviations should be the subject of further research.

Microscopical anatomy of the peripheral nervous system: An essential notion for understanding the pathophysiology of very early classic Guillain-Barré syndrome.

The aim of this paper is to analyze the pathophysiological mechanisms acting in very early classic Guillain-Barré syndrome (GBS) (≤4 days of symptomatic onset). In this inaugural period, both in GBS and its animal model, experimental autoimmune neuritis, the outstanding pathological feature is inflammatory edema predominating in proximal nerve trunks, particularly spinal nerves, and possibly in preterminal nerve segments. Nerve trunks external to the subarachnoid angle possess epi- perineurium that is relatively inelastic and of low compliance. Here such edema can increase endoneurial fluid pressure that, when sufficiently critical, may stretch the perineurium and constrict transperineurial microcirculation, compromising blood flow and producing the potential for ischemic nerve injury, whose consequence is rapid partial or complete loss of nerve excitability. These histopathological features correlate well with electrophysiological and imaging findings reported in early GBS stages. Spinal nerve edema and ischemia help to understand the pattern of Wallerian-like degeneration observed in the axonal form of GBS, predominating in motor spinal roots at their exit from the dura matter (spinal nerves) with centrifugal distribution in more distant motor nerve trunks, and centripetal extension to the distal portion of intrathecal roots. The similarity of initial pathogenic mechanisms between demyelinating and axonal forms of GBS explains why an early increase of serum biomarkers of axonal damage is detected in both forms. In conclusion, knowledge of the microscopic anatomy of the peripheral nervous system is an essential step for a reliable understanding of pathophysiological mechanisms operating in the early phase of any classic GBS subtype.

Fiber-type composition and 3D capillary analysis of the human splenius capitis muscle.

Despite the significance of neck muscles in musculoskeletal disorders, their microscopic anatomy remains poorly characterized. This study examined the splenius capitis muscle, focusing on its fiber-type composition, fiber size, and capillary network characteristics. For comparison and validation, the vastus lateralis muscle was also analyzed. Muscle samples from 13 young male subjects (mean age ± SD: 35.7 ± 8.6 years) were collected within 24-h post-mortem during autopsy. Myosin heavy chain (MyHC) isoform expression was characterized immunohistochemically in 10 μm sections, while the capillary network architecture was assessed in 100 μm sections. Immunofluorescence staining, confocal microscopy, and 3D image analysis were employed to quantify capillary tortuosity, anisotropy, branch density (Br dens), and the length of capillaries per muscle volume (LV), per muscle fiber length (LL), per fiber surface area (LS), and per fiber volume (LVf). Compared to the vastus lateralis muscle, the splenius capitis muscle had a higher percentage of type 1 fibers (51.2% vs 39.7%), fewer type 2a fibers (16.2% vs 31.4%), and smaller fiber diameters (35.5-40.9 μm vs 47-56.1 μm). It also displayed lower Br dens (P = 0.0069), higher anisotropy (P = 0.0004), and lower LL (P < 0.0001) but higher LVf (P = 0.0486). In the splenius capitis muscle, body mass index (BMI) negatively correlated with LV (P = 0.0155), LS (P = 0.0091), LVf (P = 0.0137), and anisotropy (P = 0.0425), and positively correlated with tortuosity (P = 0.0473), indicating a reduction in the capillary network. In the vastus lateralis muscle, only LV (P = 0.0161) decreased with high BMI. This study characterized the fiber-type composition, fiber size, and 3D capillary network of the splenius capitis muscle, establishing a baseline for investigations into pathological muscle alterations.

Interlaboratory and cross-platform accessibility of time-of-flight wood identification database

The mass spectral database of tree species built by US Fish and Wildlife Service has thousands of entries and has been a valuable resource to combat illegal logging and international trade. The database was and continues to be constructed using a particular ambient ionization time-of-flight mass spectrometry (TOF-MS) platform in the agency branch in Ashland, OR, with which queries of unknown wood samples are investigated exclusively. Laboratories that operate different MS instruments also have an interest in using the database if they can produce valid matches to known samples compatible with the database. Four species were selected for inter-laboratory comparison using Orbitrap MS instruments and the equivalent TOF-MS platform with direct analysis in real time ionization of institution-sourced wood samples. Identities of the known samples were confirmed by examination of their microscopic wood anatomy. Orbitrap analysis was able to identify each species as confidently as the TOF instruments, often with less variation in spectra but not necessarily greater mass accuracy or better-matched signal abundance to the control database. The Orbitrap program also had to be doubled to two scanned mass ranges appended for greater peak intensity, before spectra could be correctly matched to the database, but the program was successful.

Fascial plane blocks: from microanatomy to clinical applications.

In the last 20 years, advancements in the understanding of fasciae have significantly transformed anaesthesia and surgery. Fascial plane blocks (FPBs) have gained popularity due to their validated safety profile and relative ease. They are used in various clinical settings for surgical and nonsurgical indications. Growing evidence suggests a link between the microscopic anatomy of fasciae and their mechanism of action. As a result, knowledge of these aspects is urgently needed to better optimise pain management. The purpose of this review is to summarise the different microscopic aspects of deep/muscular fascia to expand our understanding in the performance of FPBs. There is ample evidence to support the role of FPBs in pain management. However, the exact mechanism of action remains unclear. Fasciae are composed of various structural elements and display complex anatomical characteristics at the microscopic level. They include various cell types embedded within an extracellular matrix abundant in collagens and hyaluronan. Increasingly, numerous studies demonstrated their innervation that contributes to their sensory functions and their role in proprioception, motor coordination and pain perception. Lastly, the diversity of the cellular and extracellular matrix, with their viscoelastic properties, is essential to understanding the FPBs' mechanism of action. Physicians must be aware of the role of fascial microscopic anatomy and better understand their properties to perform FPBs in a conscious manner and enhance pain management.

Comparative microscopic anatomy of Schizomida – 2. The rostrosoma and the pharyngeal suction pump

This paper tests hypotheses of independent parallel evolution of the rostrosoma among euchelicerate taxa by analyzing the microscopic anatomy and histology of the rostrosoma of Uropygi (Schizomida and Thelyphonida) and comparing it with the morphology of the snout region in other euchelicerates. The study employs analysis of multiple histological serial sections, μCT-imaging, and graphical as well as computer-based 3D reconstruction. Results of the study are that Thelyphonida and Schizomida share the same morphology of the rostrosoma. The rostrosoma of both groups contains a unique arrangement of musculature that is functionally interpreted as pre-oral suction pump. This is followed by a pharyngeal suction pump. The muscles of the pharyngeal suction pump attach to the epistome and the epipharyngeal sclerite. Neither Schizomida nor Thelyphonida possess a postcerebral suction pump as reported earlier. The microscopic anatomy of the rostrosoma of both taxa is unique and does not compare with any of the other euchelicerates, thus supporting the idea of independent evolutionary origin of the rostrosoma. Thelyphonida, Amblypygi and Scorpiones share the occurrence of a large epipharyngeal/epistomal sclerite with associated musculature, which is a feature that lines up with the Arachnopulmonata concept. A comparison with all Euchelicerata taxa shows that the snout region is formed by homologous morphological elements but the specific arrangement, additions and reductions shape the formation of the rostrosoma, so that parallel evolution of homologous parts of the arachnid ground pattern can be assumed that has formed those elements into convergent morphologies.

Assessing the Efficacy of Tragal Pumping in a Novel Tympanostomy Tube-Rat Model.

Tragal pumping (TP) is a practice of pushing on the tragus to raise pressure within the external auditory canal and is a commonly recommended adjunctive maneuver believed to facilitate the introduction of ototopical medications into the middle ear cavity via a tympanostomy tube. To investigate the efficacy of TP in the penetration of eardrops into the middle ear cavity via tympanostomy tube, we established the novel tympanostomy tube-rat model. We investigated the histology of the middle ear to determine the efficacy in moving fluid into the middle ear. Prospective controlled animal study. Animal laboratory in a university hospital. Ten rats were recruited, and a tympanostomy tube insertion and green dye eardrops into outer ears were performed on bilateral ears. TP was performed only on 1 ear and was not applied on the other ear in each rat. Green dye in a middle ear cavity in hematoxylin and eosin-stained temporal bone sections was evaluated by blinded experts in microscopic anatomy (staining grade) and by using Image J software (staining level). The results of these 2 methods were statistically validated. The staining grade (P < .001) and the staining level (P < .001) were significantly higher in the ears which we applied TP than in the control ears. The results of 2 methods were significantly and positively correlated (r = .898, P < .001). Our results showed that the TP accelerate the penetration of eardrops into the middle ear cavity in the tympanostomy tube-rat model.

Morphology of human sinoatrial node and its surrounding right atrial muscle in the global obesity pandemic-does fat matter?

The sinus node (SN) is the main pacemaker site of the heart, located in the upper right atrium at the junction of the superior vena cava and right atrium. The precise morphology of the SN in the human heart remains relatively unclear especially the SN microscopical anatomy in the hearts of aged and obese individuals. In this study, the histology of the SN with surrounding right atrial (RA) muscle was analyzed from young non-obese, aged non-obese, aged obese and young obese individuals. The impacts of aging and obesity on fibrosis, apoptosis and cellular hypertrophy were investigated in the SN and RA. Moreover, the impact of obesity on P wave morphology in ECG was also analyzed to determine the speed and conduction of the impulse generated by the SN. Human SN/RA specimens were dissected from 23 post-mortem hearts (preserved in 4% formaldehyde solution), under Polish local ethical rules. The SN/RA tissue blocks were embedded in paraffin and histologically stained with Masson's Trichrome. High and low-magnification images were taken, and analysis was done for appropriate statistical tests on Prism (GraphPad, USA). 12-lead ECGs from 14 patients under Polish local ethical rules were obtained. The P wave morphologies from lead II, lead III and lead aVF were analyzed. Compared to the surrounding RA, the SN in all four groups has significantly more connective tissue (P ≤ 0.05) (young non-obese individuals, aged non-obese individuals, aged obese individuals and young obese individuals) and significantly smaller nodal cells (P ≤ 0.05) (young non-obese individuals, aged non-obese individuals, aged obese individuals, young obese individuals). In aging, overall, there was a significant increase in fibrosis, apoptosis, and cellular hypertrophy in the SN (P ≤ 0.05) and RA (P ≤ 0.05). Obesity did not further exacerbate fibrosis but caused a further increase in cellular hypertrophy (SN P ≤ 0.05, RA P ≤ 0.05), especially in young obese individuals. However, there was more infiltrating fat within the SN and RA bundles in obesity. Compared to the young non-obese individuals, the young obese individuals showed decreased P wave amplitude and P wave slope in aVF lead. Aging and obesity are two risk factors for extensive fibrosis and cellular hypertrophy in SN and RA. Obesity exacerbates the morphological alterations, especially hypertrophy of nodal and atrial myocytes. These morphological alterations might lead to functional alterations and eventually cause cardiovascular diseases, such as SN dysfunction, atrial fibrillation, bradycardia, and heart failure.

Adenosquamous Cell Carcinoma Secondary to Chronic Osteomyelitis of the Tibia - Rare Case Report

Osteomyelitis is an infection with progressive destruction of bone tissue involving the bone and articular cartilage with its medullary canal. Chronic osteo-myelitis treatment is challenge for the orthopaedician. The bone microscopic anatomy and also the microorganism biofilms and their ability to adapt to their surrounding environment. It’s tough for the antibiotics and disinfectants to breach the biofilm barrier and kill these microorganism colonies. Cutaneous neoplasm are a rare complication developing after a chronic bone infection. The incidence and prevalence of these cutaneous tumor/neoplasm following chronic bone infection continues to increase despite the increasing awareness to the disease process, and medical advances in early diagnosis and early treatment. Most common neoplasm after a chronic bone infection are squamous cell carcinoma and rarely sarcoma or lymphoma. 1 In our study we report adenosquamous cell carcinoma arising from chronic osteomyelitis of tibia for which above knee amputation was done.

Clinical High-Resolution Imaging of the Inner Ear by Using Magnetic Resonance Imaging (MRI) and Cone Beam Computed Tomography (CBCT).

Imaging of the delicate inner ear morphology has become more and more precise owing to the rapid progress in magnetic resonance imaging (MRI). However, in clinical practice, the interpretation of imaging findings is hampered by a limited knowledge of anatomical details which are frequently obscured by artifacts. Corresponding review articles are as rare in journals as they are in reference books. This shortness prompted us to perform a direct comparison of imaging with anatomical whole-mount sections as a reference. It was the intention of this paper to compare the microscopic anatomy of a human inner ear as shown on anatomical whole-mount sections with high-resolution MRI and cone beam computed tomography (CBCT). Both are available in clinical routine and depict the structures with maximum spatial resolution. It was also a goal of this work to clarify if structures that were observed on MRI in a regular manner correlate with factual inner ear anatomy or correspond with artifacts typical for imaging. A fresh human anatomical specimen was examined on a clinical 3-Tesla MRI scanner using a dedicated surface coil. The same specimen was then studied with CBCT. In each imaging modality, high-resolution 3D data sets which enabled multiplanar reformatting were created. In the second step, anatomical whole-mount sections of the specimen were cut and stained. This process enabled a direct comparison of imaging with anatomical conditions. Clinical MRI was able to depict the inner ear with remarkable anatomical precision. Strongly T2-weighted imaging protocols are exquisitely capable of showing the fluid-filled components of the inner ear. The macular organs, ampullar crests and cochlear aqueduct were clearly visible. Truncation artifacts are prone to be confused with the delicate membrane separating the endolymphatic from the perilymphatic compartment. However, it was not possible to directly depict this borderline. With the maximum resolution of magnetic resonance tomography, commonly used in everyday clinical practice, even the smallest details of the inner ear structures can be reliably displayed. However, it is important to distinguish between truncation artifacts and true anatomical structures. Therefore, this study can be useful as a reference for image analysis.

Systematic histology and evidence for the male reproductive activity of Amphibalanus amphitrite (Darwin, 1854)

AbstractThe striped acorn barnacle, Amphibalanus amphitrite, a taxon of Balanidae, is commonly found along Thailand's coastline. In this study, we used histological methods to describe the microscopic anatomy of A. amphitrite. All samples (n = 30) were obtained from the seagrass beds of Libong Island, Thailand, in the Andaman Sea. Histological observation of various longitudinal sections from specimens of A. amphitrite provides clear insights into the organization of organ systems in the species. The digestive tract was observed to be mainly divided into four subregions, including the cuticle‐lined mouth and esophagus, which is characterized by a high columnar epithelium, the stomach, and the intestine. The accessory organ, including the digestive gland, exhibited lobulated structures and was covered with low columnar epithelial cells on a thin layer of smooth muscle. Furthermore, we examined the reproductive system, including both the ovary and testes, as well as the process of gametogenesis. Testicular development was predominantly observed during active breeding seasons throughout the observation.

An Extensive Study Regarding the Microscopic Anatomy of the Early Fetal Human Optic Nerve.

The development of the optic nerve and its surrounding tissues during the early fetal period is a convoluted period because it spans both the organogenesis period and the fetal period. This study details the microscopic anatomy and histoembryology of the optic nerve in embryos during the early fetal period, including the second half of the first trimester of pregnancy. Serial sections through the orbit of variously aged embryos allowed us to analyze the nerve in both longitudinal and transverse aspects. A histological assessment and description of the structures surrounding and inside the nerve were performed, highlighting the cellular subtypes involved. By employing immunohistochemical techniques, we could characterize the presence and distribution of astrocytes within the optic nerve. Our findings suggest that by the 8th gestational week (WG) the structures are homologs to all the adult ones but with an early appearance so that maturation processes take place afterward. By this age, the axons forming the nerve are definitive adult axons. The glial cells do not yet exhibit adult phenotype, but their aspect becomes adult toward the 13th week. During its development the optic nerve increases in size then, at 14 weeks, it shrinks considerably, possibly through its neural maturation process. The morphological primordium of the blood-nerve barrier can be first noted at 10 WG and at 13 WG the morphological blood-nerve barrier is definitive. The meningeal primordium can be first noted as a layer of agglomerated fibroblasts, later toward 13 WG splitting in pachymeninx and leptomeninges and leaving space for intrinsic blood vessels.

Gross as well as microscopic anatomy and physiological functions of fetal placenta in Jaffrabadi buffaloes

The present study was conducted to know the gross morphology and histo-morphological structure of fetal placenta in Jaffrabadi buffaloes. Parameters like calf weight, placental weight, numbers, and size of cotyledons were observed in Jaffrabadi buffaloes and morphologically, fetal cotyledons were convex and non-pendunculated in Jaffrabadi buffaloes were found. Histological studies of small and large cotyledons showed extensive branching of secondary and tertiary villi that were longer, slender, and well developed in Jaffrabadi buffalo. A less developed basal lamina was seen in small cotyledon whereas developed basal lamina with numerous capillaries and connective tissue were observed in the large cotyledon. The diameter of trophoblast giant cells (TGC) in larger cotyledons were significantly (P&lt;0.05) than the small cotyledons in expelled placenta at full term in Jaffrabadi buffaloes. A distinct distribution of carbohydrate and lipids in cotyledons were observed between large and small cotyledons as evident by acid mucopolysaccharides, neutral polysaccharides, and sudanophilic staining. Specific staining for calcium with Alizarin red stain showed that calcium is not present in a noticeable amount in small and large cotyledons. Isolation and culture of Jaffrabadi placental cells in M-199 medium with antibiotics and 2% FBS results in the efficient production of progesterone, estrogen, and testosterone. This study has shown that trophoblast cells are the actual sites for steroid hormone production. These cultured placental cells (1x106 cells/ ml) produce Progesterone, Estradiol-17β and Testosterone in the range of 1.72 to 2.12, 16.03 to 19.51 and 0.51 to 0.58 ng/ml, respectively in Jaffrabadi buffalo.

Brain atlas of the annual Garcialebias charrua fish.

Annual fish have become attractive study models for a wide range of disciplines, including neurobiology. These fish have developed different survival strategies. As a result, their nervous system is under considerable selective pressure when facing extreme environmental situations. Fish from the Austrolebias group exhibit rapid neurogenesis in different brain regions, possibly as a result of the demanding conditions of a changing habitat. Knowledge of cerebral histology is essential for detecting ontogenic, anatomical, or cytoarchitectonic changes in the brain during the short lifespan of these fish, such as those reflecting functional adaptive plasticity in different systems, including sensory structures. The generation of an atlas of Garcialebias charrua (previously known as Austrolebias charrua) establishes its anatomical basis as a representative of a large group of fish that share similarities in their way of life. In this work, we present a detailed study of both gross anatomy and microscopic anatomy obtained through serial sections stained with the Nissl technique in three orientations: transverse, horizontal, and parasagittal planes. This atlas includes accurate drawings of the entire adult brain of the male fish Garcialebias charrua, showing dorsal, ventral, and lateral views, including where emergence and origin of cranial nerves. This brain atlas allows us to understand histoarchitecture as well as the location of neural structures that change during adult neurogenesis, enabling comparisons within the genus. Simultaneously, this atlas constitutes a valuable tool for comparing the brains of other fish species with different behaviors and neuroecologies.

Microscopic anatomy of the organs in the body

Microscopic anatomy of the organs in the body

The Internal Anatomy and Water Current System of Cambrian Archaeocyaths of South China.

Archaeocyaths are a group of extinct filter feeders that flourished in the early Cambrian period and occupied an important position in the evolution of basal fauna and the early marine ecosystem. However, the detailed morphological and anatomical information of this group are still unclear due to insufficient fossil material and limited experimental analyses. Here, we report exquisitely preserved phosphatized archaeocyathan fossil cups, ca. 515 million years old, from the top of the Shuijingtuo Formation (Series 2, Stage 3) and the Xiannüdong Formation (Series 2, Stage 3) of the Yangtze Platform, South China. Detailed observation of their external morphology via scanning electron microscopy (SEM) and micro-computed tomography (Micro-CT) analysis revealed detailed information of their internal structure. They have a typical double-walled cup, with the perforated inner and outer walls concentrically distributed, but the structure between the two walls differs. The inverted cone-shaped cups have radially distributed septa between the walls. Perforated septa connect the two walls. The low and columnar cups have canals between the two walls, forming the network. These pores and cavities constitute an important component of the water current system (pumping and filtering water with a network of canals and chambers) and influence the process of filtration in the cup. In comparison to traditional thin-section analysis, the combination of SEM and Micro-CT analysis on phosphatized archaeocyaths presented in this study further explored the detailed internal structure and finely reconstructed the microscopic overall morphology and anatomy, which provide important information to help us understand the systematic taxonomy, anatomy, and morphology of archaeocyaths during the Cambrian period.

Assessing the histomorphology, and microscopic composition of the triangular fibrocartilage complex [TFCC] of the wrist joint: A cadaveric observational study

TFCC, being a complicated structure, located on the ulnar side of the wrist is composed of multiple distinct anatomic entities which together play a critical role in wrist biomechanics. The anatomy of TFCC has not been extensively studied in the Indian population. To elucidate the microscopic anatomy and composition of the triangular fibrocartilage complex of the wrist joint using haematoxylin-eosin and Verhoff Van Gieson staining methods. Samples collected from 40 specimens (20 right and 20 left limbs) were placed in 10% neutral buffered formalin for fixation. Paraffin-embedded blocks were prepared and tissue sections were taken at 7-micron thickness. The slides were subjected to H&amp;E and VVG staining following standardized protocol. The morphological structure of the seven components of triangular fibrocartilage complexes was assessed. The articular disc consisted of densely packed interlaced fibrocartilage with sparse blood vessels. Radioulnar ligaments showed densely-packed-parallel or interlaced- collagen-bundles. A mixture of tight and loose parallel tissue was observed in the sub-sheath of the extensor carpi ulnaris muscle, the ulnar-triquetral (UTL), and the ulnar-lunate ligament (ULL). Irregular morphological composition and loose connective tissue predominated in the ulnar-carpal meniscus (UCM). Blood vessels were observed in the epi-fascicular/ fascicular areas of the UTL, interstitial region of ULL and UCM. The microscopic anatomy of TFCC was complex owing to the varied nature of its entities. An understanding of the distribution of connective tissue, blood vessels, and elastic fibres would be of immense help in planning arthroscopic procedures.

Correlating Histology Examination Performance with Histopathology Examination Results in Longitudinally Followed Pre-Clinical Students: A Comparative Analysis.

&lt;p&gt;&lt;strong&gt;Background and Objective&lt;/strong&gt;: In the undergraduate medical curriculum, various subjects synergize throughout the years, culminating in the completion of the MBBS course. Histology, a branch of Anatomy, specifically deals with microscopic anatomy. Concurrently, Histopathology, an extension of histology, is a vital facet of Pathology. Proficiency in comprehending the normal histological structure of the human body is imperative, enabling a comprehensive understanding of the microscopic foundations and the diagnosis of diseases during one's medical education. This study was designed to compare and contrast the MBBS students&amp;rsquo; exam performance in Histology with that of Histopathology through a longitudinal follow up.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;A study sample comprised of MBBS students of College of Medicine, Northern Border University, Arar, KSA who had completed final exams for both subjects between the academic years 2016 to 2021; excluding the academic year affected by Covid-19. Mean scores for the two subjects were computed, and statistical analysis, including the calculation of p-values, was performed using SPSS.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Results&lt;/strong&gt;: The mean scores for Histology and Pathology for the sample students were 75.6% and 77.26% respectively, exhibited a striking similarity and, indicated a robust correlation (p&amp;lt;0.001) between the averages of the two subjects.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Conclusion&lt;/strong&gt;: The study suggests that, under typical circumstances, a solid grasp of histology enhances comprehension in histopathology. Students with a thorough understanding of normal human tissue are better equipped to predict changes or disruptions in pathological samples with increased accuracy&lt;/p&gt;

Gross and microanatomic description of the dental pads of the Florida manatee, Trichechus manatus latirostris, and their importance to mastication

ObjectiveFlorida manatee feeding ecology is critical to species survival, but the role of dental pads in feeding has received limited attention. This study characterized the gross and microscopic anatomy of the manatee’s dorsal and ventral dental pad in relation to these structures’ importance in mastication, which furthers our understanding of manatee feeding and health. DesignWhole heads from 6 animals (4 male and 2 female) of varying sizes were examined grossly. Sections (5 µm) from throughout the dorsal and ventral dental pads were stained with Hematoxylin and Eosin to document microanatomy. The thickness of the epithelium and stratum corneum were measured. ResultsThe ventral dental pad epidermal (1129–3391 µm) and stratum corneum (331–1848 µm) thickness increased with increased body size. The dorsal dental pad epidermal (690–1988 µm) and stratum corneum (121–974 µm) thickness varied relative to size. The dental pad anatomy, including the thickened stratum corneum, indicates an importance similar to molars in grinding and physically breaking up plant material. Extensive appendages including filiform-like papillae and well-developed rete were observed and likely provide physical support for mastication. ConclusionWhile the sample size limits specific conclusions based on sex or age, it provides a good overview of the anatomy of the dental pads. The manatee is the only mammal known to have a ventral dental pad and the well-developed grinding surfaces demonstrates a crucial role in mastication for these structures. These dental pads should be evaluated during health checks and necropsies and considered in future research on manatee’s feeding mechanisms.