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Distal Branches (distal + branch)
Selected AbstractsNerve supply of the brachioradialis muscle: Surgically relevant variations of the extramuscular branches of the radial nerveCLINICAL ANATOMY, Issue 7 2005Maria D. Latev Abstract The brachioradialis muscle is utilized in tendon-transfer operations, carried out for a variety of purposes. The extramuscular branches of the radial nerve to the brachioradialis were dissected and studied in 43 embalmed cadaveric specimens. The number of primary and secondary branches and the spatial locations of their origins and muscle-entry points was determined for each specimen. All distances were measured relative to the lateral epicondyle. A wide anatomic variation was observed in both the nerve branching pattern as well as the number and locations of muscle-entry points. A single primary nerve branch was found in 20 specimens, or 46.5% of the cases. On an average, single primary nerve branches arose from the radial nerve 30 mm proximal to the lateral epicondyle. In 16 of these cases, the primary branch splits into two to four secondary branches, and in four cases there was only one branch entering the muscle. Seventeen specimens had two primary branches whose origin points were separated by 5 to 40 mm with an average of 15 mm. In seven of these seventeen cases one or both of the primary branches split into secondary branches. Six specimens had three primary branches; the origin points of the most proximal and the most distal branch were separated by up to 30 mm with an average of 13 mm. Excluding the four cases with extensive fanning into multiple thin branches, the number of muscle-entry points ranged from 1 to 4 (mean 2.7). The locations of the muscle-entry points for all specimens were widespread ranging from 50 mm proximal and 40 mm distal to the lateral epicondyle with an average at 6 mm proximal to the lateral epicondyle. The greatest distance between muscle-entry points was 50 mm in a single specimen. In surgical procedures involving dissection of the brachioradialis muscle more proximal than 50 mm distal to the elbow, the extramuscular branch(es) of the radial nerve branches to the brachioradialis may be at risk. Clin. Anat. 18:488,492, 2005. © 2005 Wiley-Liss, Inc. [source] Effects of variability in anatomical reconstruction techniques on models of synaptic integration by dendrites: a comparison of three internet archivesEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2004Tibor Szilágyi Abstract The first step in building a realistic computational neuron model is to produce a passive electrical skeleton on to which active conductances can be grafted. For this, anatomically accurate morphological reconstructions of the desired cell type are required. In this study compartmental models were used to compare from a functional perspective three on-line archives of rat hippocampal CA1 pyramidal cell morphologies. The topological organization of cells was found to be similar for all archives, but several morphometric differences were observed. The three-dimensional size of the cells, the diameter and tortuosity of dendrites, and the electrotonic length of the main apical dendrite and of the branches in stratum lacunosum moleculare were dissimilar. The experimentally measured kinetics of somatically recorded inhibitory postsynaptic currents evoked in the stratum lacunosum moleculare (data from the literature) could be reproduced only using the archives that contained cells with an electrotonically short main apical dendrite. In the amplitude attenuation of the simulated postsynaptic currents and the voltage escape from the command potential under voltage clamp conditions, a two- to three-fold difference was observed among archives. Upon activation of a single model synapse on distal branches, cells with low dendritic diameter showed a voltage escape larger than 15 mV. The diameter of the dendrites influenced greatly the results, emphasizing the importance of methods that allow an accurate measurement of this parameter. Our results indicate that there are functionally significant differences in the morphometric data available in different archives even if the cell type, brain region and species are the same. [source] Living related small bowel transplantation in children: 3-dimensional computed tomography donor evaluationPEDIATRIC TRANSPLANTATION, Issue 1 2004Fabrizio Panaro Abstract:, The evaluation of the small bowel vascular anatomy of living small bowel donors (LSBD) is usually performed with conventional angiography (CA). Recently, angio computed tomography (CT) has become a valid study of the vascular anatomy for kidney and liver living donors. We studied the applicability of angio CT with 3-D reconstruction (3-D-ACT) in the evaluation of LSBD. Potential LSBDs for pediatric transplant underwent both CA and 3-D-ACT to evaluate the anatomy of the distal branches of the superior mesenteric artery and vein. Angio-CT was performed with General Electric Lightspeed Scanner. The 3-D reconstruction was performed on the TeraRecon workstation. Adverse reactions, contrast dosage, test duration, invasiveness, hospital-stay, patient discomforts and accuracy were evaluated. Four potential donors (four female; mean age: 30.5 yr; mean BMI: 28.4) underwent both tests. Adverse reactions correlated to contrast agent used (90 mL CA, 150 mL 3-D-ACT) were not reported. CA required a hospitalization of 6 h as opposed to immediate discharge after the 3-D-ACT. The CA required the placement of transfemoral catheter and therefore greater patient discomfort than with 3-D-ACT. The 3-D-ACT arterial images were rated as equivalent to CA, however, 3-D-ACT venous images were rated better than the CA in all cases. CT-angiography with 3-D reconstruction is an acceptable method for vascular evaluation. When compared with routine angiography, it is less invasive, better tolerated and faster, but does require a significantly greater volume of venous contrast. 3-D-ACT also offers a better evaluation of the venous phase, and thus may become the test of choice to evaluate the vascular anatomies of LSBD candidates. [source] Water relations of baobab trees (Adansonia spp.PLANT CELL & ENVIRONMENT, Issue 6 2006L.) during the rainy season: does stem water buffer daily water deficits? ABSTRACT Baobab trees are often cited in the literature as water-storing trees, yet few studies have examined this assumption. We assessed the role of stored water in buffering daily water deficits in two species of baobabs (Adansonia rubrostipa Jum. and H. Perrier and Adansonia za Baill.) in a tropical dry forest in Madagascar. We found no lag in the daily onset of sap flow between the base and the crown of the tree. Some night-time sap flow occurred, but this was more consistent with a pattern of seasonal stem water replenishment than with diurnal usage. Intrinsic capacitance of both leaf and stem tissue (0.07,0.08 and 1.1,1.43 MPa,1, respectively) was high, yet the amount of water that could be withdrawn before turgor loss was small because midday leaf and stem water potentials (WPs) were near the turgor-loss points. Stomatal conductance was high in the daytime but then declined rapidly, suggesting an embolism-avoidance strategy. Although the xylem of distal branches was relatively vulnerable to cavitation (P50: 1.1,1.7 MPa), tight stomatal control and minimum WPs near ,1.0 MPa maintained native embolism levels at 30,65%. Stem morphology and anatomy restrict water movement between storage tissues and the conductive pathway, making stored-water usage more appropriate to longer-term water deficits than as a buffer against daily water deficits. [source] | ||||||||||