Anatomia Histologia Embryologia最新文献

The osseous tentorium cerebelli attaches to the inner surface of the skull and separates the cerebrum from the cerebellum, thereby dividing the cranial cavity into the rostral and caudal cranial fossae. The transverse sinus canal/groove, located near the attachment margin of the tentorium cerebelli, houses the transverse venous sinus. During surgical procedures, it is essential to understand the anatomical position of the osseous tentorium cerebelli and transverse venous sinus using the surface structure of the skull as a landmark. This study compared the positional variation of the attachment site of the osseous tentorium cerebelli and transverse sinus canal/groove relative to the external landmarks of the skull, specifically the external occipital protuberance and nuchal crest in small dogs. We analysed computerised tomography data from 23 client-owned dogs of four small breeds without brain or skull lesions. Using sagittal plane images from computed tomography (CT), the osseous tentorium cerebelli deviation distance (OTCDD) and the transverse sinus canal or groove deviation distance (TSCGDD) from external landmarks were measured. Both OTCDD and TSCGDD exhibited interindividual variation. In the interbreed comparison, the OTCDD was significantly greater in Chihuahuas than in Toy Poodles and Miniature Dachshunds. A strong correlation was observed between OTCDD and TSCGDD. This study demonstrated both interindividual and interbreed diversity in the anatomical positioning of the osseous tentorium cerebelli and transverse sinus canal/groove. Nevertheless, these structures consistently maintained a close spatial relationship. The findings contribute to a more detailed anatomical understanding of the skull in small-breed dogs and may assist in optimising craniectomy procedures.

Sheep have been used as an ideal translational model for embryological studies of the central nervous system. The objective of the present study was to establish normal quantitative parameters for the cerebellum during intrauterine development in sheep, using unbiased design-based stereological methods. Twenty sheep embryos were divided into four gestational age groups (9–11, 12–14, 15–17 and 18–20 weeks of gestation). The orientator method was used to obtain isotropic, uniform and random sections. The fractional volume of white matter, grey matter and different layers was estimated by a point-counting system. The cerebellar surface area was estimated through the use of test lines. The total volume of the cerebellum increased from 0.1142 ± 0.02644 cm³ to 1.4717 ± 0.3558 cm³ during development. The volume of white matter increased from 0.0785 ± 0.02616 cm³ to 0.5316 ± 0.12677 cm³, and the volume of grey matter showed an increase from 0.0785 ± 0.02616 cm³ to 0.5316 ± 0.12677 cm³. The volume of the external granular, molecular and internal granular layers increased from 0.009 ± 0.00249 cm³, 0.0078 ± 0.00175 cm³, 0.0189 ± 0.00403 cm³ to 0.0942 ± 0.01986 cm³, 0.2311 ± 0.04582 cm³, 0.5367 ± 0.1666 cm³, respectively. The surface area of the cerebellum increased from 5.54 ± 1.75 cm² to 53 ± 11.6 cm². All aforementioned parameters showed a positive significant (p < 0.05) correlation with gestational age. The standard data of this research could be used as a reference for the accurate surveying of cerebellar development and also for practical applications in veterinary embryological neurology.

This study provides the first description of the anatomy and histology of the female internal genital organs of Mico marcai. Descriptions were based on samples collected from two free-ranging specimens. As in other species of Platyrrhini, the ovaries were oval-shaped. Histological findings suggest both females were at the beginning of the luteal phase, as shown by the presence of luteal tissue in the ovaries and the high incidence of follicular atresia. As described in other primates, branching longitudinal folds and a tunica muscularis were seen in uterine tubes in M. marcai. The tunica muscularis is responsible for the peristaltic action that carries the oocyte towards the uterus. The uterus had a collagen-rich endometrium with high numbers of simple tubular glands. Different from other primates, in M. marcai the vagina was lined with non- keratinized stratified squamous epithelium with PAS-positive vaginal fluid. Measurement of serum levels of reproductive hormones is warranted to explain histological changes in female internal genital organs of M. marcai in the different phases of the reproductive cycle.

This study was conducted to reveal the gross and histological structures and area size of the rhinarium on 20 yak heads. Macroscopic examinations were used to reveal macroscopic structures; Mallory's triple staining and SEM examination were used for histological structures, and the Fıjı program was used to determine the rhinarium area size. In macroscopic examinations, it was determined that the yak rhinarium consists of dark, moist and hairless skin located between the nostrils and the upper lip and that it features a philtrum in the upper lip region. In SEM examinations, the skin in this region was composed of epidermis and dermis layers and that the skin surface had areas of different sizes separated by primary grooves containing single, double or triple epidermal domes. In triple staining, it was determined that the skin was composed of epidermis, dermis and hypodermis. The dermis and epidermis layers were tightly connected to each other, and the stratum corneum was thick in the epidermis layer, while connective tissue threads and serous glands and ducts were dense in the dermis layer. According to the findings obtained from the study, it was concluded that the tip of the yak's nose has differentiated to adapt to high altitude, cold and harsh weather conditions; the philtrum seen in the upper lip section of the rhinarium can be used to distinguish yak from other cattle breeds, and the dome areas of different shapes and numbers seen on the epidermal surface can be used in the individual identification of animals.

Yes-associated protein 1 (YAP1), a core effector of the Hippo pathway, regulates organogenesis and tumourigenesis. However, its role in uterine lymphatic and glandular morphogenesis remains unclear. Frozen sections revealed the overall developmental pattern of uterine lymphatic vessels. The immunohistochemistry results from postnatal day 1 (P1) to P7 indicate that both blood and lymphatic vessels extend into the uterine muscle layer without glandular bud formation, accompanied by YAP1 mainly expressing in the cytoplasm of the uterus. From P8 to P10, the number of blood vessels and lymphatic vessels increases, glandular buds begin to form, and YAP1 nuclear expression rises. By P21, the tissue structure of the uterus resembles that of adults; YAP1 expression sharply decreases. By P28, YAP1 expression is nearly absent. We demonstrate that YAP1 expression dynamically shifts from cytoplasmic to nuclear localisation during postnatal uterine development in mice, correlating with lymphatic vessel invasion into the myometrium (P1–P10) and glandular maturation (P8–P21). Vascular development precedes lymphangiogenesis, suggesting angiogenesis-dependent nutrient delivery is critical for early uterine growth. These findings reveal YAP1 as a key coordinator of uterine morphogenesis, providing insights into gynaecological disorder mechanisms.

In human medicine, the enthesis, or tendon-to-bone insertion, is generally considered a linked entity or ‘enthesis organ’ and plays a crucial biomechanical role. This study aimed to histologically assess the equine proximal third interosseus muscle (suspensory ligament) enthesis in 10 pelvic limbs from 7 horses. The area of the proximal third interosseus muscle enthesis was divided into 6 compartments based on post-mortem computed tomography and prepared for histology using haematoxylin/eosin and trichrome staining. The proximal third interosseus muscle enthesis showed a fibrocartilaginous nature. All adult entheses exhibited a characteristic four-layered structure consisting of ligament, uncalcified fibrocartilage, calcified fibrocartilage and bone. Juvenile specimens lacked clear layering, suggesting ongoing endochondral ossification. One or more smooth, regular tidemarks separated the uncalcified and calcified fibrocartilage, while the margins separating the ligament and bone from the fibrocartilage layer showed pronounced irregular interdigitations. Mean cellularity, fibrocartilage thickness and interdigitation size and shape varied among specimens. The fibrocartilaginous nature of the proximal third interosseus muscle enthesis in the equine pelvic limb supports the role of a stress dissipation mechanism and may have implications in the biomechanics and pathology of proximal third interosseus muscle enthesis injuries.