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The portal venous system is a network of vessels that carry blood from the capillary beds of the major abdominal organs to the liver. During embryology, the portal venous system can develop aberrantly, leading to vascular connections between the portal and systemic venous circulation known as portosystemic shunts. The purpose of this comparative review with a few short representative case reports was to present the similarities and differences in portosystemic shunts in humans and small animals and their radiologic evaluation. Aberrant vascular connections between the portal and systemic venous circulation enable portal blood to bypass metabolism and detoxification in the liver, leading to significant clinical implications. Portosystemic shunts are very rare in humans, but these connections are much more common in small animals, affecting up to 0.6% of small animals. Portosystemic shunts can be congenital or acquired and are divided into intrahepatic and extrahepatic types. Because of its ability to accurately assess abdominal structures, large vessels, and their flow dynamics without anesthesia, ultrasonography has become the first imaging modality employed for the diagnostic evaluation of portosystemic shunts in both humans and small animals. This is usually followed by contrast-enhanced computed tomographic angiography in order to better define the exact shunt anatomy and to plan treatment. It is important to understand the embryology, anatomy, pathology, and pathophysiology of portosystemic shunts in order to understand the findings of radiologic imaging and to initiate appropriate treatment. [ABSTRACT FROM AUTHOR]

Purpose: Horizontal instability is a common problem after acromioclavicular joint injuries. The aim of this study was to evaluate if there is a difference regarding horizontal stability between an anatomical and a non-anatomical configuration of the double tunnel coraco-clavicular ligament reconstruction of the acromioclavicular joint. Methods: Thirteen acromioclavicular joints of human cadaveric shoulders in ethanol-glycerin fixation were included in the study and underwent cyclic anterior and posterior translational testing at a load of 70 N using an electromechanical uniaxial testing machine. The shoulders were randomly assigned to the following groups: double coraco-clavicular tunnel technique in an anatomical configuration (DCTa) and double coraco-clavicular tunnel technique in an inverse configuration of the anatomical position (DCTb). The dislocation was recorded with a 3D optical measuring system. Results: The total horizontal displacement (p10 = 0.0221; p5000 = 0.082) was significantly higher for the non-anatomical reconstruction (DCTb) compared to the anatomical reconstruction (DCTa) after every measured amount of cycles. The increase in displacement for DCTb group was overall higher than the increase in displacement for DCTa group but without significance. Conclusion: Reconstruction of the CC ligaments in an anatomical configuration with two suture devices results in a significantly higher stability of the AC joint in the horizontal plane than reconstruction of the CC ligaments in a non-anatomical configuration. Based on the results of this biomechanical in vitro study, the use of a double coraco-clavicular reconstruction should focus on an anatomically correct position of the suture devices. [ABSTRACT FROM AUTHOR]

The aim of this study is to quantify muscular and connective tissue volumes of extraocular muscles (EOM) in humans with no ophthalmological disease using stereology. EOM from five cadaveric non-strabismic humans were obtained. The number of muscle fibers in 5,000 mm2 and volume density (Vv) of muscle and collagen were measured using stereology. Comparisons between antagonist EOM were conducted using Wilcoxon signed rank test for paired samples. A secondary analysis examining differences between pairs of EOM was also conducted. Bilateral tests were performed, and significance was set at 0.05. The horizontal rectus muscles (medial and lateral rectus) had the highest Vv of muscle and the lowest Vv of collagen. The inferior rectus muscle tended to have a fewer number of fibers per 5,000 mm2 than the rest of the EOM. However, these differences did not reach statistical significance. This is the first published study describing the normal histology of human EOM using stereology. Our investigation, through the quantification of the proportion of muscle and collagen tissue, as well as the number of muscle fibers in 5,000 m2, establishes normal stereological parameters for EOM of humans without ophthalmological disease. [ABSTRACT FROM AUTHOR]

Detailed knowledge of the possible anatomical and morphometric variations of the infraorbital foramen (IOF) is important for ensuring safe and successful regional anesthesia, and for avoiding iatrogenic nerve injuries during surgery on the middle third of the face. To conduct a morphometric study on the IOF, correlating this with sex and side of the cranium. Two hundred forty-two crania were used (148 male and 94 female). Measurements were made with the aid of digital calipers with precision to 0.01 mm. Presence of foramina and their multiplicity was also observed. The data were analyzed descriptively and analytically. Statistical significance was stipulated as 5% (P≤0.05). The IOF was found bilaterally in all the crania, and 26 of them presented multiplicity. The distance from the IOF to the anterior nasal spine was greater in males on both sides (P<0.001). Statistical differences between the sexes were also seen in relation to the following morphometric variables: height of the left IOF (P=0.007), width of the right IOF (P=0.004), and width of the left IOF (P=0.008), and the measurements were also larger among males. The IOF was present in all the crania and on both sides. It was morphometrically larger in males, on both sides. [ABSTRACT FROM AUTHOR]

ABSTRACT William K. Gregory was one of the most influential authors defending the existence of an evolutionary trend in vertebrates from a higher degree of polyisomerism (more polyisomeric or 'serial' anatomical structures arranged along any body axis) to cases of anisomerism (specialization or loss of at least some original polyisomeric structures). Anisomerism was the subject of much interest during the 19th and the beginning of the 20th centuries, particularly due to the influence of the Romantic German School and the notion of 'primitive archetype' and because it was conceptually linked to other crucial biological issues (e.g. complexity, scala naturae, progress, modularity or phenotypic integration). However, discussions on anisomerism and related issues (e.g. Williston's law) have been almost exclusively based on hard tissues. Here we provide the first detailed empirical test, and discussion, of anisomerism based on quantitative data obtained from phylogenetic and comparative analyses of the head and forelimb muscles of gnathostomes. Our results strongly support the existence of such a trend in both forelimb and head musculature. For instance, the last common ancestor ( LCA) of extant tetrapods likely had 38 polyisomeric muscles ( PMs) out of a total of 70 forelimb muscles (i.e. 54%), whereas in the LCAs of extant amniotes and of mammals these numbers were 38/73 (52%) and 21/67 (31%), and in humans are 11/59 (19%). Interestingly, the number of PMs that became specialized during the forelimb evolutionary transition from the LCA of extant tetrapods to humans (13) is very similar to the number of PMs that became lost (14), indicating that both specialization and loss contributed equally to the trend towards anisomerism. By contrast, during the evolution of the head musculature from the LCA of gnathostomes to humans a total of 27 PMs were lost whereas only one muscle became specialized. Importantly, the evolutionary trend towards anisomerism is not related to a general trend leading to the presence of fewer muscles in derived taxa, because for instance humans have more head muscles in total, but many less head polyisomeric muscles than early gnathostomes and extant fish such as sharks, and than early tetrapods and amphibians such as salamanders. This is because new muscles have also been acquired during gnathostome evolution (e.g. facial muscles of mammals). Interestingly, many new PMs have also been acquired during head evolution (but subsequently lost during the transitions towards humans), whereas only a few new PMs were acquired during forelimb evolution. Our comparisons and review of the literature indicate that there is also a trend towards anisomerism during development, thus providing a further example of a parallel between ontogeny and phylogeny, e.g. some forelimb PMs (e.g. contrahentes, intermetacarpales) become specialized or lost (re-absorbed) during human ontogeny and some head PMs (e.g. constrictores branchiales) become lost during salamander ontogeny. This review will inform future discussions on modularity, complexity, body plans, phenotypic integration and macroevolution, which should ideally include soft tissues and the use of new tools (e.g. anatomical networks) in order to provide a broader and more integrative understanding of these relevant subjects. [ABSTRACT FROM AUTHOR]

Background The distal soft tissue procedure is an integral part of hallux valgus surgery, providing soft tissue balance and alignment restoration of the first metatarsophalangeal joint. Various approaches have been established to this end. For techniques that do not include a separate dorsal incision, lateral release may be achieved via a transarticular approach or via a medial incision and a dorsal flap over the first metatarsal. Compared to the double-incision technique, these techniques are not only cosmetically superior and thus meet the demands of most surgeons and patients. Material and methods Using six pairs of frozen cadaveric feet, lateral release was performed using one of the above techniques in a randomized manner with pair comparison. The specimens were then dissected and the completeness of the release as well as any damage to anatomic structures was documented. Results The transarticular technique enabled complete release of the metatarsal-sesamoid suspensory ligament (MSL) and the transverse and oblique head of the adductor hallucis muscle in five of six specimens. The comparative technique enabled the same in only two of six cases for the adductor hallucis muscle and in four cases for the MSL. The transarticular approach achieved complete release of the lateral joint capsule in three of six specimens, whereas the dorsal approach achieved no release in any specimen. Neither of the methods caused any macroscopic injury to the surfaces of the first metatarsophalangeal joint. The examined arteries, veins, and nerves remained intact in all specimens treated with the transarticular approach, but dorsal release resulted in one documented injury to the first dorsal metatarsal artery and its concomitant veins. Conclusions Compared to release by dissection superficially to the extensor tendons, transarticular release provides a more complete lateral release and less injuries to neurovascular bundles. Further anatomic and clinical studies are needed, however, before conclusive recommendations can be made. [ABSTRACT FROM AUTHOR]

This study evaluated clinical outcomes following intraoperative use of adult mesenchymal stem cells ( MSCs) in various oral reconstructive procedures. PubMed was searched without language restrictions from 2000 to 2011 using the search words stem cell, oral surgery, tissue engineering, sinus lift, bone regeneration and combinations of these. Inclusion criteria were intraoperative use of MSCs in the study design. Reference lists of the articles found were searched for other related studies. Eighteen clinical trials using MSCs for sinus augmentation were found: five case reports on the repair of large bony defects and six studies on ridge augmentation and healing of alveolar sockets after third molar extraction. The findings suggest that MSCs are capable of producing in vivo bone, re-establishing lost tissue and facilitating placement of dental implants. Use of MSCs would reduce patient morbidity because of a less stressful harvesting technique than that of autogenous bone. The majority of clinical trials indicate that MSCs can produce bone in vivo. However, a satisfactory outcome was not seen in all studies, and due to the diversity of study designs, a 'golden approach' cannot be determined. Before use of MSCs can be considered as a first-choice treatment, more predictable outcomes and better long-term prognoses need to be established. Conventional bone grafting remains the gold standard. [ABSTRACT FROM AUTHOR]

Objectives The effect of gender on anatomic structures and various body systems were illustrated in the literature. The purpose of this study was to identify the influence of gender and tooth loss on incisive canal characteristics and buccal bone dimensions in the anterior maxilla. Materials and methods Computed tomographies ( CTs) of 417 male and 516 female patients in four dental clinics were included in this study. The diameter and the length of the incisive canal; width and the length of the bone anterior to the canal; palatal bone length, root length, and root width of the central incisor teeth were measured and recorded from CT sections. Results Mean incisive canal length was 11.96 ± 2.73 mm and 10.39 ± 2.47 mm in men and women, respectively, ( P < 0.05). In men, mean canal diameter was 2.79 ± 0.94 mm whereas in women it was 2.43 ± 0.85 mm and this difference was statistically significant ( P < 0.05). Men had significant higher buccal bone dimensions (length and width of the bone anterior to the canal) than women. Absence of teeth in the anterior maxilla decreased incisive canal length and buccal bone dimensions; however, canal diameter remain unchanged. Conclusions Present results suggested a gender related differences in anatomic features of incisive canal and surrounding buccal bone. In addition, crestal canal diameter, buccal bone length, and thickness parameters might be different in distinct countries. [ABSTRACT FROM AUTHOR]

Background/Aim. Both superior parietal lobule (SPL) of dorsolateral hemispheric surface and precuneus (PEC) of medial surface are the parts of posterior parietal cortex. The aim of this study was to determine the numerical density (NV) of pyramidal neurons in the layer V of SPL and PEC and their potential differences. Methods. From 20 (40 hemispheres) formaline fixed human brains (both sexes; 27 - 65 years) tissue blocks from SPL and PEC from the left and right hemisphere were used. According to their size the brains were divided into two groups, the group I with the larger left (15 brains) and the group II with the larger right hemisphere (5 brains). Serial Nissl sections (5 µm) of the left and right SPL and PEC were used for stereological estimation of NV of the layer V pyramidal neurons. Results. NV of pyramidal neurons in the layer V in the left SPL of brains with larger left hemispheres was significantly higher than in the left SPL of brains with larger right hemisphere. Comparing sides in brains with larger left hemisphere, the left SPL had higher NV than the right one, and then the left PEC, and the right SPL had significantly higher NV than the right PEC. Comparing sides in brains with the larger right hemisphere, the left SPL had significantly higher NV than left PEC, but the right SPL had significantly higher NV than left SPL and the right PEC. Conclusion. Generally, there is an inverse relationship of NV between the medial and lateral areas of the human posterior parietal cortex. The obtained values were different between the brains with larger left and right hemispheres, as well as between the SPL and PEC. In all the comparisons the left SPL had the highest values of NV of pyramidal neurons in the layer V (4771.80 mm-3), except in brains with the larger right hemisphere. [ABSTRACT FROM AUTHOR]

Purpose: For many years, the anatomy of the medial knee corner has been reported. However, it is not exactly clear how all these structures function together. The purpose of this study is to identify and try to understand the relationship between the posteromedial corners of the knee using three-dimensional visualization techniques. Materials and methods: This study comprises of 10 knees from adult corpses. Images were acquired from the dissection of different layers of the posteromedial compartment of the knee using a camera Nikon D40 and AF-S Nikkor 18-55 mm (Nikon Corp., Japan) placed on a slide bar. The pair of images was processed using Callipyan 3D or Anabuilder software (Ana builder, France) that transforms the two different images of the same structure with the intrapupillary distance proportion into one anaglyphic image. Results: During knee dissection, pictures were taken and transformed into three-dimensional images that become more realistic with the use of special glasses. The images were made during the dissection of the three layers of the posteromedial compartment of the knees. Conclusions: Posteromedial corner ligament structures are quite complex and are not always clearly described in the literature. Three-dimensional images of these structures can help better understanding its anatomy. [ABSTRACT FROM AUTHOR]

The mammalian facial muscles are a subgroup of hyoid muscles (i.e. muscles innervated by cranial nerve VII). They are usually attached to freely movable skin and are responsible for facial expressions. In this study we provide an account of the origin, homologies and evolution of the primate facial muscles, based on dissections of various primate and non-primate taxa and a review of the literature. We provide data not previously reported, including photographs showing in detail the facial muscles of primates such as gibbons and orangutans. We show that the facial muscles usually present in strepsirhines are basically the same muscles that are present in non-primate mammals such as tree-shrews. The exceptions are that strepsirhines often have a muscle that is usually not differentiated in tree-shrews, the depressor supercilii, and lack two muscles that are usually differentiated in these mammals, the zygomatico-orbicularis and sphincter colli superficialis. Monkeys such as macaques usually lack two muscles that are often present in strepsirhines, the sphincter colli profundus and mandibulo-auricularis, but have some muscles that are usually absent as distinct structures in non-anthropoid primates, e.g. the levator labii superioris alaeque nasi, levator labii superioris, nasalis, depressor septi nasi, depressor anguli oris and depressor labii inferioris. In turn, macaques typically lack a risorius, auricularis anterior and temporoparietalis, which are found in hominoids such as humans, but have muscles that are usually not differentiated in members of some hominoid taxa, e.g. the platysma cervicale (usually not differentiated in orangutans, panins and humans) and auricularis posterior (usually not differentiated in orangutans). Based on our observations, comparisons and review of the literature, we propose a unifying, coherent nomenclature for the facial muscles of the Mammalia as a whole and provide a list of more than 300 synonyms that have been used in the literature to designate the facial muscles of primates and other mammals. A main advantage of this nomenclature is that it combines, and thus creates a bridge between, those names used by human anatomists and the names often employed in the literature dealing with non-human primates and non-primate mammals. [ABSTRACT FROM AUTHOR]

Abstract: This paper reviews information on the biological behavior of inorganic cobalt in humans and laboratory animals and proposes a model of the systemic biokinetics of inorganic cobalt in adult humans. The model was developed as part of an effort to update the models of the International Commission on Radiological Protection (ICRP) for addressing intakes of radionuclides by workers but is also applicable to environmental or medical exposures to inorganic forms of radiocobalt. The model can be used in conjunction with any respiratory, gastrointestinal, or wound model that provides predictions of the time-dependent feed of cobalt to blood. In contrast to the ICRP''s current systemic model for cobalt, which is a simple open catenary system, the proposed model is constructed within a physiologically realistic framework that depicts recycling of cobalt between blood and tissues and transfer from blood to excretion pathways. Compared with the ICRP''s current model, the proposed model yields similar predictions of whole-body retention but substantially different predictions of the systemic distribution of cobalt as a function of time after uptake to blood. [Copyright &y& Elsevier]

Context Computer-aided instruction is used increasingly in medical education and anatomy instruction with limited research evidence to guide its design and deployment. Objectives To determine the effects of (a) learner control over the e-learning environment and (b) key views of the brain versus multiple views in the learning of brain surface anatomy. Design Randomised trial with 2 phases of study. Participants Volunteer sample of 1st-year psychology students (phase 1, n = 120; phase 2, n = 120). Interventions Phase 1: computer-based instruction in brain surface anatomy with 4 conditions: (1) learner control/multiple views (LMV); (2) learner control/key views (LKV); (3) programme control/multiple views (PMV); (4) programme control/key views (PKV). Phase 2: 2 conditions: low learner control/key views (PKV) versus no learner control/key views (SKV). All participants performed a pre-test, post-test and test of visuospatial ability. Main outcome measures A 30-item post-test of brain surface anatomy structure identification. Results The PKV group attained the best post-test score (57.7%) and the PMV group received the worst (42.2%), with the 2 high learner control groups performing in between. For students with low spatial ability, estimated scores are 20% lower for those who saw multiple views during learning. In phase 2, students with the most static condition and no learner control (SKV) performed similarly to those students in the PKV group. Conclusions Multiple views may impede learning, particularly for those with relatively poor spatial ability. High degrees of learner control may reduce effectiveness of learning. [ABSTRACT FROM AUTHOR]

Introduction There is much subjective discussion, but few empirical data that explore how students approach the learning of anatomy. Aims Students' perceptions of successful approaches to learning anatomy were correlated with their own approaches to learning, quality of learning and grades. Methods First-year medical students ( n = 97) studying anatomy at an Australian university completed an online survey including a version of the Study Process Questionnaire (SPQ) that measures approaches to learning. The quality of students' written assessment was rated using the Structure of Observed Learning Outcomes (SOLO) taxonomy. Final examination data were used for correlation with approaches and quality of learning. Results Students perceived successful learning of anatomy as hard work, involving various combinations of memorisation, understanding and visualisation. Students' surface approach (SA) scores (mean 30 ± 3.4) and deep approach (DA) scores (mean 31 ± 4.2) reflected the use of both memorisation and understanding as key learning strategies in anatomy. There were significant correlations between SOLO ratings and DA scores ( r = 0.24, P < 0.01), between SA scores and final grades ( r = − 0.30, P < 0.01) and between SOLO ratings and final grades ( r = 0.61, P < 0.01) in the subject. Conclusions Approaches to learning correlate positively with the quality of learning. Successful learning of anatomy requires a balance between memorisation with understanding and visualisation. Interrelationships between these three strategies for learning anatomy in medicine and other disciplines require further investigation. [ABSTRACT FROM AUTHOR]

The authors compared perception of the standard and reversed Müller-Lyer figures between pigeons (Columbio livio) and humans (Homo sopiens). In Experiment 1, pigeons learned to classify 6 lengths of target lines into "long" and "short" categories by pecking 2 keys on the monitor, ignoring the 2 brackets so placed that they would not induce an illusion. In the test that followed, all 3 birds chose the "long" key more frequently for the standard Müller-Lyer figures with inward-pointing brackets (><)than for the figures with outward-pointing brackets (<>). The subjects' responses were accountable by neither overall lengths of the figures nor horizontal gaps between the 2 brackets. For the reversed figures, effects of the brackets were absent. These results suggested that the pigeons perceived the standard Müller-Lyer illusion but not the reversed one. Experiment 2 confirmed that humans perceived both types of the illusion. Pigeons and humans may perceive the same illusory figures in different ways. [ABSTRACT FROM AUTHOR]

Abstract: Fungiform papillae density, which can be used in a variety of circumstances as an indicator of taste function [L.M. Bartoshuk, V.B. Duffy, I.J. Miller, PTC/PROP tasting: anatomy, psychophysics and sex effects, Physiol. Behav. 56 (1994) 1165–1171; I.J. Miller, F.E. Reedy, Variation in human taste bud density and taste intensity perception, Physiol. Behav. 47 (1990) 1213–1219; J.R. Zuniga, N. Chen, C.L. Phillips, Chemosensory and somatosensory regeneration after lingual nerve repair in humans, J. Oral Maxillofac. Surg. 55 (1997) 2–13], was measured on the dorsal surface of the anterior tongue of living humans using a digital camera and a videomicroscope. Both procedures provided similar results, with the camera providing a more rapid, portable and flexible imaging procedure. Subsequently, the camera was successfully used to identify small regions of the anterior tongue which provide reliable measures of fungiform papillae density that correlate highly with the total number of fungiform papillae on the anterior tongue. [Copyright &y& Elsevier]

The purpose of this experiment was to examine vestibular contributions at specific times during the initiation of walking in human subjects. Subjects began walking forward at the sound of an auditory tone, with vision present or occluded. Galvanic vestibular stimulation (GVS) was delivered with the anode electrode on the right or left side at either: (1) onset of the anticipatory postural adjustment (APA), (2) toe-off of the first swing limb (TO) or (3) heel contact of the first swing limb (HC). Ground reaction forces and kinematic data were collected. Upper body (roll angles from head, trunk and pelvis) and lower body (foot placement) data were analysed to determine whether the timing and magnitude of the response to GVS, and therefore the level of vestibular contribution, was modulated at different points during the initiation of gait. With vision present and occluded, the magnitude of the lower body response varied depending on the event in the gait cycle at which the stimulation was delivered. These novel results demonstrate evidence that vestibular weighting during gait initiation is dependent upon the specific gait initiation events. Upper body roll also exhibited magnitude differences between events. However, these changes are proposed to occur due to the transition from a stationary position into a dynamic state, prompting the increased weighting of vestibular information. With vision present no significant changes were seen in the segment roll response. The observations suggest a distinction in vestibular regulation of upper body roll versus foot placement for successful completion of the gait initiation task. Changes in upper body roll are influenced by the dynamic nature of the task, whereas foot placement changes are modulated based on the event during gait initiation at which GVS is delivered. [ABSTRACT FROM AUTHOR]

The dependence of electromagnetic energy absorption at 900 MHz in the human head on its anatomy and its modeling are investigated for RF-sources operating in the very close proximity of the head. Different numerical head phantoms based on MRI scans of 3 different adults were used with voxel sizes down to 1 mm/sup 3/. Simulations of the absorption were performed by distinguishing the electrical properties of up to 13 tissue types. In addition simulations with modified electric parameters and reduced degrees of complexity were performed. Thus, the phantoms greatly differ from each other in terms of shape, size, and internal anatomy. The numerical results are compared with those of measurements in a multitissue phantom and 2 homogeneous phantoms of different shapes and sizes. The results demonstrate that size and shape are of minor importance, Although local SAR values depend significantly on local inhomogeneities and electric properties, the volume-averaged spatial peak SAR obtained with the homogeneous phantoms only slightly overestimates that of the worst-case exposure in the inhomogeneous phantoms. [ABSTRACT FROM AUTHOR]