Springer Science and Business Media LLC

Situs inversus totalis is well known, but its comprehensive description has been rare, especially on the internal view of the heart. For discussions based on recent results in developmental biology, the present study demonstrates a region- or part-specific manner of the inverted morphology found in a male donated cadaver and discusses the pathogenetic mechanisms of situs inversus in the human. Therein, clearly inverted morphologies existed in the coronary vessels, the apex position (dextracardia), connections between the heart and great vessels, the internal view of the atrium, the aortic arch with the three major branches, lung and liver segments and abdominal gastrointestinal tract. However, the ventricular internal view suggested incomplete laterality, such as tricuspid atrioventricular valves for both ventricles. The cardiac conductive system appeared not to be inverted but abnormal. The thoracic aorta and pulmonary artery took an L-spiral position with modifications. The inferior vena cava was located on the right side of the abdominal aorta. However, the left-sided kidney was located superior to the right-sided kidney. Similarly, the testicular vessels did not exhibit a clearly inverted morphology, but were almost normal. Therefore, the posterior mediastinal and retroperitoneal structures appeared to exhibit neutral laterality, incomplete inverted morphology or even normal morphology. According to the personal history and present histology, this specimen was unlikely to correspond to Kartagener’s syndrome. The present observations seem to be consistent with recent findings in mutant models of laterality disturbances, in which a single gene or molecule is responsible for the changes in a region-specific manner.

Little research has been carried out on the gross visceral anatomy of the Otariidae, and the anatomical information for the southern fur seals, Arctocephalus spp., is scant. The aim of the present study was to describe the external and internal conformation, and the sanguineous irrigation of the heart of Arctocephalus australis. Twelve hearts of Arctocephalus australis were studied by simple dissection. In the right ventricle the trabeculae carneae were well developed and there were three or more papillary muscles. In the left ventricle there were two papillary muscles, subatrialis and subauricularis, attached to the parietal wall. There was also a great development of trabeculae carneae which occupied almost all of the ventricle, from the left atrioventricular valve up to the proximities of the expulsion route. A large quantity of muscular strands were found extending themselves between the trabeculae carneae, becoming more dense and forming a network when near the apex. The distribution of the branches of the coronary arteries was highly variable and no heart was similar to another one in this sense. In the majority of the hearts the subsinosal interventricular branch proceeded from the right coronary artery. It is concluded that there were many differences between the heart of the Arctocephalus australis and the heart of the domestic dog, contrary to what has been suggested for other genera of Otariidae.

Even in the rapidly changing field of cadaver dissection, published guide books still play an important role in the anatomy lab. However, commercial manuals with lengthy volumes and inflexible copyrights have several limitations which can be complemented by open-source manuals. Recently, the authors have manufactured and distributed a free electronic dissection manual (anatomy.co.kr), where descriptions are written concisely and images are drawn schematically. Moreover, simplified signs are employed to represent the cadaver viewing angles and manner of dissection. Based on the original files of this manual, other anatomists can revise and utilize the descriptions and figures. We expect many updated versions of our manual to be shared between students all over the world.

This study describes the facial pillar system in dolichocephalic and brachycephalic breeds of dogs, and highlights its differences. Knowledge of facial pillar system anatomy is imperative to carry out successful fracture repair. The aim of our study was to describe the pillar system of the facial skeleton in dogs, and compare different shapes of dog skulls using native skulls, radiographs and computed tomography (CT). The heads of brachycephalic and dolichocephalic dogs were investigated following a maceration process using trans-illumination, radiography and CT. Ground sections were created from bones of the facial skeleton for investigation of osteon directions. This study has revealed that the facial skeleton of the dog has numerous sinuses supported by vertically and horizontally oriented bone pillars. These pillars can be divided into five principal regions in dolichocephalic skulls and six principal regions in brachycephalic skulls. Radiographic imaging of both the brachiocephalic and dolichocephalic skulls was not capable of discerning bone pillars. Computed tomography transverse and horizontal section images discerned all pillars observed in the illuminated skulls.

For realistic virtual dissection, the sectioned images of a cadaver are a desirable material because of their high resolution and real body color. After a volume model is made of the sectioned images, it can be piled or peeled at the intended thickness as if a structure’s surface is expanded and shrunken. The purpose of our study was to confirm whether laparoscopic and endoscopic exploration of the processed volume model plays a part in anatomy investigation. The ascending colon was outlined in serially sectioned images and accumulated to build a volume model. While the volume model was being piled or peeled, the ascending colon was observed laparoscopically and endoscopically in comparison with the original sectioned image. The trial efficiently demonstrated layers of the colon wall and surrounding tissues which could not be visualized by conventional macroscopic or microscopic techniques. The availability and contribution of this new method will be confirmed by application to other various organs.

The retrosplenial cortex consists of areas 29a–d, each of which has different connections with other cortical and subcortical regions. Although these areas also make complex interconnections that constitute part of a neural circuit subserving various functions, such as spatial memory and navigation, the details of such interconnections have not been studied comprehensively. In the study reported here, we investigated the organization of associational and commissural connections of areas 29a–d within the retrosplenial cortex in the rat, using the retrograde tracer cholera toxin B subunit and anterograde tracer biotinylated dextran amine. The results demonstrated that each of these areas has a distinct set of interconnections within the retrosplenial cortex. Each area interconnects strongly along the transverse axis of the retrosplenial cortex: area 29a, area 29b, caudal area 29c, and caudal area 29d connect with each other, and rostral area 29c and rostral area 29d connect with each other. In the longitudinal direction, rostral-to-caudal projections from rostral areas 29c and 29d to areas 29a and 29b and caudal areas 29c and 29d are strong, whereas reciprocal caudal-to-rostral projections are relatively weak. Although most of the intrinsic connections are homotopical, contralateral connections are weaker and less extensive than ipsilateral connections. These findings suggest that each retrosplenial area may not only process specific information somewhat independently but that it may also integrate and transmit such information through intrinsic connections to other areas in order to achieve retrosplenial cortical functions, such as spatial memory and learning.