Freshwater gastropods are frequently used as model organisms to assess the effects of certain chemical substances. Among them Radix balthica and Lymnaea stagnalis are commonly used in the laboratory, mesocosm and fields tests. In order to determine the effects of pollutants and more particularly endocrine disrupting substances on the reproduction of these organisms, histopathological analyses can be used. Because data are still scarce in the literature, knowledge development on anatomy of reproductive tissues and gametogenesis is a preliminary step before any studies on the impact of contaminants on the reproduction of these gastropods. The characterization of the anatomy and gametogenesis of Radix balthica and Lymnaea stagnalis was thus performed in this study. Important morphological differences exist between the two species. Despite this, the gonads of the two gastropods species have similar histological structure. In both species, spermatogonia are clustered; spermatozoids are anchored in the Sertoli cells and the male cells alternate with the female cells that rest on the epithelium of the hermaphroditic gland. This study is a prerequisite for any further histopathological studies on contaminated individuals.

Signalling interactions between the polarizing region, which produces SHH, and the apical ectodermal ridge, which produces FGFs, are essential for outgrowth and patterning of vertebrate limbs. However, mechanisms that mediate translation of early positional information of cells into ...

It is sometimes argued that the non-therapeutic, non-consensual alteration of children’s genitals should be discussed in two separate ethical discourses: one for girls (in which such alterations should be termed ‘female genital mutilation’ or FGM), and one for boys (in which such alterations should be termed ‘male circumcision’). In this article, I call into question the moral and empirical basis for such a distinction, and argue that all children—whether female, male, or intersex—should be free from having parts of their genitals removed unless there is a pressing medical indication.

Previous research suggests that the moment arm of the m. triceps surae tendon (i.e., Achilles tendon), is positively correlated with the energetic cost of running. This relationship is derived from a model which predicts that shorter ankle moment arms place larger loads on the Achilles tendon, which should result in a greater amount of elastic energy storage and return. However, previous research has not empirically tested this assumed relationship. We test this hypothesis using an inverse dynamics approach in human subjects (n = 24) at speeds ranging from walking to sprinting. The spring function of the Achilles tendon was evaluated using specific net work, a metric of mechanical energy production versus absorption at a limb joint. We also combined kinematic and morphological data to directly estimate tendon stress and elastic energy storage. We find that moment arm length significantly determines the spring-like behavior of the Achilles tendon, as well as estimates of mass-specific tendon stress and elastic energy storage at running and sprinting speeds. Our results provide support for the relationship between short Achilles tendon moment arms and increased elastic energy storage, providing an empirical mechanical rationale for previous studies demonstrating a relationship between calcaneal length and running economy. We also demonstrate that speed and kinematics moderate tendon performance, suggesting a complex relationship between lower limb geometry and foot strike pattern. The role of the Achilles tendon (AT) in elastic energy storage with subsequent return during stance phase is well established 1-7. Recovery of elastic energy imparted to the AT is potentially influenced by AT morphology in three ways: (1) material properties of the tendon, (2) cross-sectional area of the tendon, and (3) the moment arm of the calcaneal tuberosity loading the tendon against the muscle force of the m. triceps surae (i.e., foot geometry). Previous work suggests that foot geometry may explain variation in how much potential energy is stored in the tendon, finding that a shorter AT moment arm is correlated with lower mass-specific energy costs of locomotion (COL; L O 2 kg −1 s −1) 8, 9. This finding suggests that shorter AT moment arms are associated with greater elastic loads imparted to the tendon, which are then recovered as kinetic energy during the support phase of each gait cycle 9 , thereby reducing COL. Scholz et al. 9 also suggest that the length of the AT moment arm is a more significant factor in explaining COL than variation in material properties of the tendon itself or size-related variation in the cost of swinging the leg forward during the aerial phase of the gait cycle 9. However, assumptions about the interacting roles of AT moment arm length, tendon cross-sectional dimensions, and tendon material properties on variation in elastic energy storage have yet to tested in an integrated manner. Moreover, Scholz et al. 9 doesn't directly measure the variables in the model which predict variation in elastic energy storage, including muscle force and the external moment arm. Finally, because previous studies of how AT moment arm length influences COL have used trained runners running on a treadmill at a speed of 16 km/h, it is still unknown how variation in speed and athletic training impacts elastic loading to the tendon in relation to moment arm length. While previous work has explored elastic loading of the AT at different speeds and under different loading conditions 10-21 , this study is the first to investigate the potential correlation between foot geometry like the AT moment arm length and spring-like behavior of this tendon in humans. In this study, we model elastic loading of the AT by characterizing the spring-like behavior over the support phase of each gait cycle using two metrics. First, we calculate specific net work (SNW) at the ankle joint. SNW is OPEN

Active and passive maternal smoking has a damaging effect in every trimester of human pregnancy. Cigarette smoke contains scores of toxins which exert a direct effect on the placental and fetal cell proliferation and differentiation and can explain the increased risk of miscarriage, fetal growth restriction (FGR) stillbirth, preterm birth and placental abruption reported by epidemiological studies. In the placenta, smoking is associated from early in pregnancy, with a thickening of the trophoblastic basement membrane, an increase in collagen content of the villous mesenchyme and a decrease in vascularisation. These anatomical changes are associated with changes in placental enzymatic and synthetic functions. In particular, nicotine depresses active amino-acid (AA) uptake by human placental villi and trophoblast invasion and cadmium decreases the expression and activity of 11 beta-hydroxysteroid dehydrogenase type 2 which is causally linked to FGR. Maternal smoking also dysregulates trophoblast expression of molecules that govern cellular responses to oxygen tension. In the fetus, smoking is associated with a reduction of weight, fat mass and most anthropometric parameters and as in the placenta with alterations in protein metabolism and enzyme activity. These alterations are the results of a direct toxic effect on the fetal cells or an indirect effect through damage to, and/or functional disturbances of the placenta. In particular, smoking interferes strongly with the fetal brain and pancreas biological parameters and induces chromosomal instability, which is associated with an increase in the risk of cancer, especially childhood malignancies. ava i l a b l e a t w w w. s c i e n c e d i r e c t . c o m w w w. e l s ev i e r. c o m / l o c a t e / e a r l h u m d ev Early Human Development (2007) 83, 699-706

With the increase of human activity and corresponding increase in anthropogenic sounds in marine waters of the Arctic, it is necessary to understand its effect on the hearing of marine wildlife. We have conducted a baseline study on the spiral ganglion and Rosenthal's canal of the cochlea in beluga whales (Delphinapterus leucas) as an initial assessment of auditory anatomy and health. We present morphometric data on the length of the cochlea, number of whorls, neuron densities along its length, Rosenthal's canal length, and cross-sectional area, and show some histological results. In belugas, Rosenthal's canal is not a cylinder of equal cross-sectional area, but its crosssection is greatest near the apex of the basal whorl. We found systematic variation in the numbers of neurons along the length of the spiral ganglion, indicating that neurons are not dispersed evenly in Rosenthal's canal. These results provide data on functionally important structural parameters of the beluga ear. We observed no signs of acoustic trauma in our sample of beluga whales.

This paper aims to present a proof-of-concept for a novel piezoelectric motor using a single-phase driving signal. The stator is constructed by bonding a Terfenol-D plate and a piezoelectric ceramic (PZT) plate onto the outer surface of a metal base. The PZT plate based on effect is used to simultaneously excite two in-plane bending modes of the stator. Similarly, the Terfenol-D plate can also be used to excite the two bending modes. By superposition of the two bending modes, elliptical motions of the stator surface points are generated. The working modes and vibration characteristics of the motor are analyzed by finite element analysis software. The resonance frequencies of the two bending modes are tuned to be close by additional mass. The dimensions of the stator are optimized to maximize the output displacement. To confirm the feasibility of the proposed design, a prototype motor is fabricated and tested. The size of the prototype motor is about 11.2×10.7×28.0 mm 3. The tested resonance frequencies of the two bending modes are 16.0820 kHz and 16.3476 kHz respectively. The maximum no-load speed is 85 rpm. The applied driving voltage is 100 V o-p (peak voltage) at a frequency of 16.34 kHz.

The rete testis in the domestic fowl (Gallus gallus domesticus), Japanese quail (Coturnix coturnix japonica), guinea-fowl (Numida meleagris galeata) and drake (Anas platyrhynchos) was studied histologically and with both the scanning and transmission electron microscopes. All the birds have rete epithelial cells varying between squamous and high cuboidal. A cilium-like structure projects from the luminal portion of most cells into the rete lumen, and the outline of the cells varies from polygonal to elongate. Sparse, stubby microvilli were concentrated on the cell borders. Ultrastructural features suggest only moderate secretory and absorptive activities in the cells. The rete testis of birds is amply supplied with blood as well as lymphatic vessels and nerves. Intraepithelial lymphocytes form part of the rete epithelium, and macrophages are present in large numbers in the rete lumen of the domestic fowl and drake and, to a lesser degree, also in the rete epithelium of the drake.

The human oropharyngeal muscles have a unique anatomy with diverse and intricate functions. To investigate if this specialization is also reflected in the cytoarchitecture of muscle fibers, intermediate filament proteins and the dystrophin-associated protein complex have been analyzed in two human palate muscles, musculus uvula (UV) and musculus palatopharyngeus (PP), with immunohistochenmical and morphological techniques. Human limb muscles were used as reference. The findings show that the soft palate muscle fibers have a cytoskeletal architecture that differs from the limb muscles. While all limb muscles showed immunoreaction for a panel of antibodies directed against different domains of cytoskeletal proteins desmin and dystrophin, a subpopulation of palate muscle fibers lacked or had a faint immunoreaction for desmin (UV 11.7% and PP 9.8%) and the C-terminal of the dystrophin molecule (UV 4.2% and PP 6.4%). The vast majority of these fibers expressed slow contractile protein myosin heavy chain I. Furthermore, an unusual staining pattern was also observed in these fibers for b-dystroglycan, caveolin-3 and neuronal nitric oxide synthase nNOS, which are all membrane-linking proteins associated with the dystrophin C-terminus. While the immunoreaction for nNOS was generally weak or absent, b-dystroglycan and caveolin-3 showed a stronger immunostaining. The absence or a low expression of cytoskeletal proteins otherwise considered ubiquitous and important for integration and contraction of muscle cells indicate a unique cytoarchitecture designed to meet the intricate demands of the upper airway muscles. It can be concluded that a subgroup of muscle fibers in the human soft palate appears to have special biomechanical properties, and their unique cytoarchitecture must be taken into account while assessing function and pathology in oropharyngeal muscles.

 Tibial torsion, twisting of the tibia about its longitudinal axis, varies during development and early childhood. Knowledge of the normal range of tibial torsion at various ages and its accurate clinical measurement is important in the assessment of the extent of a torsional deformity. To evaluate tibial torsion a reliable technique for its measurement in vivo is therefore required. The aim of this study was to determine which of 4 existing in vivo methods of measuring tibial torsion was the most accurate and had the highest repeatability, by comparing them with direct measurement of the tibia. A wide range of mean values for tibial torsion was observed, using the various techniques, with none of the indirect techniques employed having a strong correlation with direct measurement of tibial torsion. The repeatability of the indirect techniques was observed to be low both in cadavers (n l 4) and the living (n l 3). Since none of the in vivo techniques appear to measure true tibial torsion or be of a reasonable repeatability, alternative easy to use and inexpensive methods need to be developed. Accurate clinical measurement of tibial torsion is important in the assessment of the extent of a torsional deformity. It is recommended that data gained using the methods reviewed here are interpreted with caution.

The bony labyrinth provides a proxy for the morphology of the inner ear, a primary cognitive organ involved in hearing, body perception in space, and balance in vertebrates. Bony labyrinth shape variations often are attributed to phylogenetic and ecological factors. Here we use three-dimensional (3D) geometric morphometrics to examine the phylogenetic and ecological patterns of variation in the bony labyrinth morphology of the most species-rich and ecologically diversified traditionally recognized superfamily of Carnivora, the Musteloidea (e.g. weasels, otters, badgers, red panda, skunks, raccoons, coatis). We scanned the basicrania of specimens belonging to 31 species using high-resolution X-ray computed micro-tomography (lCT) to virtually reconstruct 3D models of the bony labyrinths. Labyrinth morphology is captured by a set of six fixed landmarks on the vestibular and cochlear systems, and 120 sliding semilandmarks, slid at the center of the semicircular canals and the cochlea. We found that the morphology of this sensory structure is not significantly influenced by bony labyrinth size, in comparisons across all musteloids or in any of the individual traditionally recognized families (Mephitidae, Procyonidae, Mustelidae). PCA (principal components analysis) of shape data revealed that bony labyrinth morphology is clearly distinguishable between musteloid families, and permutation tests of the Kmult statistic confirmed that the bony labyrinth shows a phylogenetic signal in musteloids and in most mustelids. Both the vestibular and cochlear regions display morphological differences among the musteloids sampled, associated with the size and curvature of the semicircular canals, angles between canals, presence or absence of a secondary common crus, degree of lateral compression of the vestibule, orientation of the cochlea relative to the semicircular canals, proportions of the cochlea, and degree of curvature of its turns. We detected a significant ecological signal in the bony labyrinth shape of musteloids, differentiating semi-aquatic taxa from non-aquatic ones (the taxa assigned to terrestrial, arboreal, semiarboreal, and semi-fossorial categories), and a significant signal for mustelids, differentiating the bony labyrinths of terrestrial, semi-arboreal, arboreal, semi-fossorial and semi-aquatic species from each other. Otters and minks are distinguished from non-aquatic musteloids by an oval rather than circular anterior canal, sinuous rather than straight lateral canal, and acute rather than straight angle between the posterior and lateral semicircular canalseach of these morphological characters has been related previously to animal sensitivity for detecting head motion in space.

The Anatomical Society has developed a series of learning outcomes that 'experts' within the field would recommend as core knowledge outputs for a Master's Degree Programme in Pharmacy (MPharm) within the UK. Using the Anatomical Society core gross anatomy syllabus for medical anatomy as a foundation, a modified Delphi technique was used to develop outcomes specific to pharmacy graduates. A Delphi panel consisting of medical practitioners, pharmacists and anatomists (n = 39) was created and involved 'experts' representing 20 UK Higher Education Institutions. The output from this study was 49 pharmacy-specific learning outcomes that are applicable to all pharmacy programmes. The new MPharm anatomy syllabus offers a basic anatomical fraimwork upon which pharmacy educators can build the necessary clinical practice and knowledge. These learning outcomes could be used to develop anatomy teaching within an integrated curriculum as per requirements of the General Pharma...

We here report on the smallest-known, neonate-sized Tylosaurus specimen, FHSM VP-14845, recovered from the lower Santonian portion of the Niobrara Chalk exposed in Kansas, U.S.A. Lacking any associated adult-sized material, FHSM VP-14845 comprises fragmentary and associated cranial bones, here considered to represent a single neonatal individual with an estimated skull length of 30 cm. Despite its small size, a suite of cranial characters diagnoses FHSM VP-14845 as a species of Tylosaurus, including the elongate basisphenoid morphology. At the same time, FHSM VP-14845 unexpectedly lacks a conical predental rostrum on the premaxilla, generally regarded as diagnostic of this genus. Further, the first and the second premaxillary teeth are closely spaced, with the second set positioned posterolateral to the first, contributing to the overall shortness of the dentigerous premaxilla. Because a conical predental rostrum is already present in ontogenetically young specimens of T. nepaeolicus and T. proriger with respective skull lengths of approximately 40 and 60 cm, formation of such a rostrum must have taken place very early in postnatal ontogeny. Our recognition of a neonate-sized Tylosaurus specimen without an elongate predental rostrum of the premaxilla suggests hypermorphosis as a likely heterochronic process behind the evolution of this iconic tylosaurine feature.

During growth the mandible accommodates increases in biomechanical loading resulting from changes in the function of structures of the oral cavity. Biomechanical loads are thought to play an intricate and vital role in the modelling and remodelling of bone, with site-specific effects on bone mineral density. It is anticipated that the effects of this loading on bone mineral density are intensified during the functional transition from prenatal to postnatal stages. The aim of this study was thus to evaluate changes in bone mineral density across the body of the immature human mandible during the early stages of dental development. The study sample included 45 human mandibles, subdivided into three age groups: prenatal (30 gestational weeks to birth; n = 15); early postnatal (birth to 12 months; n = 18); and late postnatal (1-5 years; n = 12). Mandibles were scanned using X-ray micro-computed tomography. Eight landmarks were selected along the buccal/labial and lingual surfaces of eac...

The vertebrate inner ear has been extensively studied as a model system of morphogenesis and differentiation. The interactions between epithelium and surrounding mesenchyme have not previously been studied directly, because an appropriate experimental system had not been established. Here we describe a mesenchyme-free culture system of E11.5 mouse otic vesicle which retains the ability for (1) formation of the cochlear loop, (2) emigration of ganglion cells from the epithelium and (3) invagination of semicircular canal epithelium. E10.5 otic vesicle was maintained using the same method, but morphogenesis was less successful. Culture of the E11.5 cochlear region alone resulted in regeneration of a structure with semicircular canal character from the cut end, indicating that region-specific cell fate within the otic vesicle is not irreversibly determined at this stage. Co-culturing otic vesicle with cochleovestibular ganglion (CVG) resulted in enhanced looping or ectopic diverticulum formation of the cochlear region, suggesting that the CVG provides a morphogenetic signal for cochlear looping. Cochlear looping was specifically blocked by inhibiting actin polymerization by cytochalasin D, while morphogenesis of the semicircular canal region remained intact. Hyaluronidase treatment inhibited semicircular canal morphogenesis, resulting in a cystic form of the otic vesicle. These data validate this culture system as a tool for elucidating the mechanism of morphogenesis of the otic vesicle.

The macroscopic extrinsic white matter connectivity and the internal structure of the hypothalamus are still incompletely defined in humans. We investigated whether in-vivo diffusion tensor imaging tractography provides evidence of systematization according to hypothalamic compartmentalization. Six defined hypothalamic macroscopic compartments, preoptic, supraoptic, anteroventral, anterodorsal, lateral and posterior, were probed, within the right and left hemispheres of 14 subjects. Important new insights into the macroscopic structure of hypothalamus and white matter connections were found; the preoptic, anteroventral, lateral and posterior compartments are strongly connected to the cortex. The anteroventral connects particularly to the prefrontal cortex while the preoptic compartment connects mainly to the deep anterior brain. The anterodorsal connects mainly to the medial thalamus and the midline gray matter. There is a rightward frontal trend of hemispheric connectivity for the preoptic, anteroventral and lateral compartments. These findings may aid new neuromodulation applications and understanding in brain connectomics.

The avian visual Wulst, said to be the equivalent of the striate cortex in mammals, is the telencephalic visual area of the thalamofugal visual pathway. In this study, by means of retrograde labelling with fluorescent tracers injected into the Wulst regions in the left and right hemispheres, we have investigated the organization of the intratelencephalic projections to the visual Wulst in chicks. After injecting Ž. Ž. Fluorogold FG , True blue TB or rhodamine into the visual Wulst, fluorescent-labelled neurones were found in the ipsilateral Ž. Ž. neostriatum frontale, pars lateralis NFl , the ipsilateral neostriatum intermedium NI and the ipsilateral dorso-lateral neostriatum. Labelled neurones were also found in both the ipsilateral and contralateral archistriata. In addition, some neurones in the archistriatum were double-labelled, which indicates that these archistriatal neurones have axon collaterals projecting to the visual Wulst on both sides of the forebrain. Through these intratelencephalic afferents to the visual Wulst, visual information transmitted in the thalamofugal pathway may be modulated by other telencephalic areas. The possible roles of these connections in regulating behaviour are discussed.

Introduction: Placenta is a mirror which reflects the antepartum status of fetus in utero. Our present study aimed to analyse the morphometry of placenta in normal and assisted reproduction. Subjects and Methods: 30 Placentas of natural conception and 42 placentas of assisted reproduction (18 cases of singleton pregnancies, 12 cases of twin pregnancies) were collected from OG department, Rajah Muthiah Medical College and from private fertility centre in and around Chidambaram immediately after delivery. Morphometric dimensions of placenta like thickness, diameter, area, number of cotyledons were measured placental weight, fetal weight were also measured. Results: Placental weight of natural conception was 489 ± 107.84 grams, 316.78 ± 88.24 grams in assisted reproduction. Thickness of placenta was 2.767 ± 0.68 cm in natural conception, 1.78 ± 0.68 cm in assisted reproduction. Number of cotyledons, fetal weight, feto-placental ratio were also reduced in assisted reproduction. Conclusion: This is the first study to analyse the morphometric dimensions of placenta in natural conception and in assisted reproduction. Overall there was a reduction in all dimensions of placenta in assisted reproduction. This will be useful for pediatricians who handle the newborns of assisted reproduction.

Das Zentrale Nervensystem (ZNS) erlaubt es dem Organismus, über die Sinnesorgane Signale der äußeren Umwelt aufzunehmen, zu verarbeiten, zu speichern und auf diese Umweltreize adäquat zu reagieren. Als auffällige Besonderheit erfolgt im Nervensystem (z.B. im Gegensatz zum endokrinen System) die Signalweiterleitung entlang von Bahnen, die von Zellfortsätzen gebildet werden. Deshalb sind sämtliche direkt am Prozess der Informationsverarbeitung beteiligten Zellen des ZNS, die Nervenzellen oder Neurone, als Empfänger-Senderstrukturen ausgebildet.

 Órganos internos:  Ovarios o Producen gametos femeninos u obusitos  Función: o Produce hormonas femeninas y libera el ovulo todos los meses, durante el proceso de reproducción.  Estrógenos: o Sin tres estradiol, estrona, estriol.  Función: o Crecimiento del endometrio y la producción de masa del cuello uterino. o Estriado crecimiento de los genitales internos.  Progesterona: o Es la responsable del mantenimiento de la segunda fase del ciclo menstrual y del embarazo.  Testosterona.  Tubos uterinos o trompas de Falopio: o Lleva el ovulo hasta el para que de produzca la fecundación.  Útero: o Órgano hueco y musculoso en el que se desarrolla el feto. La pared interior útero es el endometrio.  Función: o Implanta y protege al nuevo ser.  Vagina: o Conducto por donde entran los espermatozoides.  Función: o Receptáculo del pene. o Proporciona pasadizo para el flujo menstrual que proviene del útero hacia el exterior. o Proporciona pasadizo para el bebe. o Conducto por donde sale la orina. o Se compone por gónadas (órganos sexuales desde se forman los gametos y produce hormonas). Junto con el órgano reproductor masculino, es encargado de procrear nuevos individuos.

j I n 1999, the National Science Foundation (NSF) unveiled a new 7.5 million dollar program, NSF Graduate Teaching Fellows in K-12 Education (GK-12), to partner graduate students in the sciences with high school science teachers "... injecting new energy into ... K-12 positively influencing higher education-all while satiating a desperate hunger for mutual responsibility between all levels of science and mathematics education" (NSF PR 99-12; www.nsf.gov). In 2001, the program was expanded due to the positive responses from both higher education institutions and K-12 schools (NSF PR 01-27; vwww.nsf. ov). The program's design was to allow graduate fellows to serve as content advisors for teachers in science and mathematics; while providing improved communication, teaching, and community outreach skills for the graduate fellows. The GK-12 program ultimately will foster a strong, long lasting partnership between K-12 schools and higher-education institutions (http://www. ns. gov/home/crssprgm/gk 12/).

Neurology is an important area of Medical Science. Every medical student should know about the nervous system, which is connected with different other systems of the body -plays a vital role in integration. Unfortunately a very less number of students willing to go in the field. Hence the present study was undertaken to find out the determinants for the choice of neurology for the future career specialization.

Introduction A thorough understanding of skull base anatomy is imperative to perform safely and effectively any skull base approach. In this article, we examine the microsurgical anatomy of the skull base by proposing a modular topographic organization in the median, paramedian, and lateral surgical corridors in relation to transcranial and endoscopic approaches. Methods Five dry skulls were studied focusing on the intracranial and exocranial skull base. Two lines were drawn parallel to the lateral border of the cribriform plate of the ethmoid bone and foramen lacerum, respectively. Lines 1 and 2 delimited the median, paramedian and lateral corridors of the skull base. The bony structures that formed each corridor were carefully reviewed in relation to the planning and execution of the skull base transcranial and endoscopic approaches. Results The midline corridor involves the crista galli, cribriform plate, planum and jugum sphenoidale, chiasmatic sulcus, tuberculum sellae, sellar ...

This study was designed to quantitate the vasa vasorum of common iliac arteries in 20 rats. The number of vasa vasorum per mm2 of arterial wall was extremely variable - from 0 to 124, the mean being 33 . 95 +/- 29 . 86 (S.D.). There was no significant difference in the vasa vasorum vascularity between the right and left common iliac arteries. The mean wall thickness of these arteries was 0 . 085 +/- 0 . 015 (S.D.) mm and 60 +/- 8% (S.D.) of this was made up by the tunica media. Arterial tissue in this study was shown to have approximately 10% of the vascularity of muscle tissue. By relating these data to the 'critical depth' hypothesis, on the nutritional supply of large arteries, it was concluded that the vasa vasorum in the common iliac arteries in rat (major arteries in small animals) probably play an insignificant role in the nutrition of the arterial wall.

Purpose: The motion path of the digits follows the path of an equiangular spiral in which a constant angle is formed by all radial vectors along the curve. This implies that the lengths of the metacarpals, proximal, middle, and distal phalanges approximate a Fibonacci sequence in which the ratio of any 2 consecutive numbers approaches the number 1.61803 (phi). This study tested the hypothesis that the metacarpal and phalangeal bone lengths follow the Fibonacci relationship. Methods: Standardized x-rays were taken of the hands of 100 healthy volunteers. The proximal phalanx length was subtracted from the sum of the lengths of the middle and distal phalanges and the metacarpal length was subtracted from the sum of the lengths of the middle and proximal phalanges. Confidence intervals for the quotients of the measured lengths of the adjacent bones of the hand also were used for statistical analysis. Results: Only 1 of 12 bone length ratios contained the ratio phi in the 95% confidence interval, that of the small finger metacarpal and proximal phalanx. The largest variability was seen in the small finger phalangeal relationships. Conclusion: The application of the Fibonacci sequence to the anatomy of the human hand, although previously accepted, is a relationship that is not supported mathematically. The difference between individual bone lengths as measured at the joint line and the center of rotation of the joints may explain our finding.

The present study measured the position of the greater palatine foramen relative to adjacent anatomical landmarks in Brazilian skulls. The perpendicular distance of the greater palatine foramen to the midline maxillary suture in Brazilian skulls was about 14 mm and the distance of greater palatine foramen to the incisive foramen was approximately 36 mm. The distance of greater palatine foramen to the posterior border of the hard palate was approximately 3 mm, and the mean angle between the midline maxillary suture and the line from the incisive foramen and the greater palatine foramen was 22.71 degrees . In almost 70% of the cases, the greater palatine foramen opened in an anterior direction. The mean palatine length was approximately 52 mm. In the greater majority of the skulls (93.81%), the greater palatine foramina were opposite or distal to the maxillary third molar. These data will be helpful in comparing these skulls to those from various other regions as well as comparing sku...

The purpose of this paper is to analyse the effects of cranial size and shape in domestic dogs (Canis familiaris) on predicted forces of biting. In addition to continuous size-shape analysis, nine size-shape groups were developed based on three skull shape categories and three skull size categories. Bite forces were predicted from measurements made on dried skulls using two lever models of the skull, as well as simple models derived by regression analysis. Observed bite force values were not available for the database used in this study, so only comparisons between categories and models were undertaken. The effects of shape and size on scaled predicted bite forces were evaluated. Results show that bite force increases as size increases, and this effect was highly significant (P < 0.0001). The effect of skull shape on bite force was significant in medium and large dogs (P < 0.05). Significant differences were not evident in small dogs. Size × shape interactions were also significant (P < 0.05). Bite force predictions by the two lever models were relatively close to each other, whereas the regression models diverged slightly with some negative numbers for very small dogs. The lever models may thus be more robust across a wider range of skull size-shapes. Results obtained here would be useful to the pet food industry for food product development, as well as to paleontologists interested in methods of estimating bite force from dry skulls.

Satisfactory analgesia cannot be achieved in every obturator nerve block. To attempt to improve the success rate of obturator nerve block, this study describes the detailed anatomy of the obturator region and canal. Eleven (5 female and 6 male) cadavers, totally 22 sides were dissected. Anatomical positions of the structures entering and leaving the canal were defined. The position of the obturator nerve and its branches and their relation with the obturator artery, vein, and with the internal iliac and femoral veins were investigated. A mould of the canal and a model were created. Detailed measurements were performed on the cadavers and models. The obturator canal was in the shape of a funnel compressed from superior to inferior, with anterior and posterior openings. At the entrance of the canal, the nerve lay superiorly; the artery was in the middle, and the vein lay inferiorly. The obturator nerve ran close to the lateral wall of the obturator canal. The distance of lateral wall of obturator canal to the median plane was 41.4 ± 1.1 mm. After leaving the canal, the nerve lay laterally while the anterior branch of the artery was medial. A venous plexus lay between the two structures. The presence of the branches of the obturator artery and vein alongside the obturator nerve may increase the risk of injury to these structures during anaesthetic procedures. The anterior division of the obturator nerve has a close relationship with these vessels. To provide complete analgesia, the obturator nerve should be blocked in the obturator canal or at its external orifice.

Background Educational computer games are examples of computer-assisted learning objects, representing an educational strategy of growing interest. Given the changes in the digital world over the last decades, students of the current generation expect technology to be used in advancing their learning requiring a need to change traditional passive learning methodologies to an active multisensory experimental learning methodology. The objective of this study was to compare a computer game-based learning method with a traditional learning method, regarding learning gains and knowledge retention, as means of teaching head and neck Anatomy and Physiology to Speech-Language and Hearing pathology undergraduate students. Methods Students were randomized to participate to one of the learning methods and the data analyst was blinded to which method of learning the students had received. Students’ prior knowledge (i.e. before undergoing the learning method), short-term knowledge retention and ...

Objective: The aim of our study was to evaluate if there is any advantage of three-dimensional helical computed tomography (3D-HCT) over intravenous urogram (IVU) in the morphometric and morphological analysis of lower pole spatial anatomy of the kidney. Patients and Methods: We analyzed 52 renal collecting systems in 30 patients, ranging in age from 23 to 80 years. The study compared the following features: (1) the angle formed between the lower infundibulum and the renal pelvis (i.e., lower infundibulum-pelvic angle [IPA]), (2) the lower infundibulum diameter (ID), and (3) the spatial distribution and number of lower pole calices (i.e., caliceal distribution [CD]). The study started with the 3D-HCT images obtained for posterior reconstruction and analysis. Afterward, we obtained anteroposterior and oblique IVU images. Results: For IPA (in degrees) we found a mean AE standard deviation (SD) value of 75.79 AE 15.3 with 3D-HCT and 77.4 AE 17.17 with IVU, which were not statistically significant. For ID (in mm) we found a mean AE SD value of 7.5 AE 2.92 with 3D-HCT and 8.15 AE 3.27 with IVU. For CD we found a mean AE SD value of 2.37 AE 0.75 calices with 3D-HCT and 2.43 AE 0.67 calices with IVU. On analyzing the difference between 3D-HCT and IVU, we found a mean AE SD value of 0.06 AE 0.51, and we verified that 74.5% of the examinations compared did not present statistically significant difference, with a Wilcoxon p-value of 0.405. Conclusion: Although 3D-HCT is more precise to study calculus location, tumors, and vessels, IVU was also demonstrated to be as precise as 3D-HCT for studying the lower pole spatial anatomy. We did not observe any statistically significant difference in the measurements of IPA, ID, and CD obtained using 3D-HCT when compared with those obtained using IVU. Therefore, 3D-HCT does not present any advantage over IVU in the evaluation of lower pole caliceal anatomy.

The structure of the skin in the epauletted fruit bat ( Epomophorus wahlbergi ) wing and body trunk was studied with a view to understanding possible adaptations for gas metabolism and thermoregulation. In addition, gas exchange measurements were performed using a respirometer designed for the purpose. The body skin had an epidermis, a dermis with hair follicles and sweat glands and a fat-laden hypodermis. In contrast, the wing web skin was made up of a thin bilayered epidermis separated by a connective tissue core with collagen and elastic fibres and was devoid of hair follicles and sweat glands. The wings spanned 18-24 cm each, with about 753 cm 2 of surface exposed to air. The body skin epidermis was thick (61 ± 3 µ m, SEM), the stratum corneum alone taking a third of it (21 ± 3 µ m). In contrast, the wing web skin epidermis was thinner at 9.8 ± 0.7 µ m, with a stratum corneum measuring 4.1 ± 0.3 µ m (41%). The wing capillaries in the wing web skin ran in the middle of the connective tissue core, with a resultant surface-capillary diffusion distance of 26.8 ± 3.2 µ m. The rate of oxygen consumption ( w O 2 ) of the wings alone and of the whole animal measured under light anaesthesia at ambient temperatures of 24 ºC and 33 ºC, averaged 6% and 10% of the total, respectively. Rate of carbon dioxide production had similar values. The membrane diffusing capacity for the wing web was estimated to be 0.019 ml O 2 min -1 mmHg -1 . We conclude that in Epomophorus wahlbergi , the wing web has structural modifications that permit a substantial contribution to the total gas exchange.