Diaphragme (organe)

Le diaphragme, terme anatomique créé par Gérard de Crémone, est un organe propre aux mammifères constitué d'une cloison musculo-aponévrotique faite de muscles squelettiques entourant un centre tendineux unique, qui sépare la cavité thoracique des cavités de l'abdomen (parfois regroupées sous le terme « cavité abdominopelvienne » et comprenant la cavité abdominale vraie ainsi que la cavité péritonéale derrière le péritoine). Le rôle physiologique du diaphragme est fondamental dans la ventilation pulmonaire des mammifères. Il est le plus volumineux et le plus important des muscles inspiratoires : sa contraction, en créant une dépression dans la cavité thoracique, permet l'entrée d'air dans les voies respiratoires. Son relâchement permet à l'inverse l'expiration passive. La contraction du diaphragme est périodique et , sous contrôle d'efférences provenant du tronc cérébral. Chaque contraction du diaphragme initie un cycle respiratoire. La fréquence de sa contraction définit la fréquenc

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thumb|upright=2|Poumons humains : Le est un organe intrathoracique pair de l'appareil respiratoire, permettant l'échange des gaz vitaux, notamment l'oxygène et le dioxyde de carbone. L'oxygèn

Le cœur est un organe musculaire creux qui assure la circulation sanguine en pompant le sang vers les vaisseaux sanguins et les cavités du corps à travers des contractions rythmiques. L'adjectif c

L’abdomen (du latin, de même sens) est une partie du corps humain ou du corps d'un animal. Chez l'être humain, il est également appelé ventre. Chez l'humain thumb|Abdomen masculin. thumb|

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Tissue engineering is an interdisciplinary field that broadly impacts human health. This course provides students an overview of how engineering approaches can be used to investigate and manipulate cell and tissue functions and enable students to be on the cutting edge of tissue engineering.

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Multi-segment analysis of spinal kinematics during sit-to-stand in patients with chronic low back pain

Guillaume Christe, Julien Favre, Thomas Legrand

While alterations in spinal kinematics have been frequently reported in patients with chronic low back pain (CLBP), a better characterization of the kinematics during functional activities is needed to improve our understanding and therapeutic solutions for this condition. Recent studies on healthy subjects showed the value of analyzing the spine during sit-to-stand transition (STST) using multi-segment models, suggesting that additional knowledge could be gained by conducting similar assessments in CLBP patients. The objectives of this study were to characterize three dimensional kinematics at the lower lumbar (LLS), upper lumbar (ULS), lower thoracic (LTS) and upper thoracic (UTS) joints during STST, and to test the hypothesis that CLBP patients perform this movement with smaller angle and angular velocity compared to asymptomatic controls. Ten CLBP patients (with minimal to moderate disability) and 11 asymptomatic controls with comparable demographics (52% male, 37.4 +/- 5.6 years old, 22.5 +/- 2.8 kg/m(2)) were tested using a three-dimensional camera-based system following previously proposed protocols. Characteristic patterns of movement were identified at the LLS, ULS and UTS joints in the sagittal plane only. Significant differences in the form of smaller sagittal-plane angle and smaller angular velocity in the patient group compared to the control group were observed at these three joints. This indicated a more rigid spine in the patient group and suggested that CLBP rehabilitation could potentially be enhanced by targeting movement deficits in functional activities. The results further recommended the analysis of STST kinematics using a pelvis-lumbar-thoracic model including lower and upper lumbar and thoracic segments. (C) 2016 Elsevier Ltd. All rights reserved.

Elsevier Sci Ltd2016

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Lumbar and thoracic kinematics during step-up: Comparison of three-dimensional angles between patients with chronic low back pain and asymptomatic individuals

Guillaume Christe, Julien Favre

While alterations in spinal kinematics have been repeatedly observed in patients with chronic low back pain (CLBP), their exact nature is still unknown. Specifically, there is a need for comprehensive assessments of multisegment spinal angles during daily-life activities. The purpose of this exploratory study was to characterize three-dimensional angles at the lower lumbar, upper lumbar, lower thoracic, and upper thoracic joints in CLBP patients and asymptomatic controls during stepping up with three different step heights. Spinal angles of 10 patients with nonspecific CLBP (six males; 38.7 +/- 7.2 years old, 22.3 +/- 1.6 kg/m(2)) and 11 asymptomatic individuals (six males; 36.7 +/- 5.4 years old, 22.9 +/- 3.8 kg/m(2)) were measured in a laboratory using a camera-based motion capture system. Seven out of the 12 angle curves had characteristic patterns, leading to the identification of 20 characteristic peaks. Comparing peak amplitudes between groups revealed statistically significantly smaller sagittal- and frontal-plane angles in the patient group at the upper lumbar joint with the two higher steps and at the lower lumbar joint with the higher step. Significantly reduced angles were also observed in sagittal plane at the upper thoracic joint with the two smaller steps. Moreover, a higher number of significant differences between groups was detected with the two higher steps than with the smallest step. In conclusion, this study showed the value of a comprehensive description of spinal angles during step-up tasks and provided insights into the alterations with CLBP. These preliminary results support prior research suggesting that CLBP rehabilitation should facilitate larger amplitudes of motion during functional activities.

2020

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Characterization of Cold-Formed Steel Framed/Wood Sheathed Floor and Roof Diaphragm Structures

Dimitrios Lignos

The seismic in-plane response of cold-formed steel (CFS) framed diaphragm structures has not been the subject of extensive study. The information available specific to diaphragm design in the North American CFS design standard is based on limited experimental work and the extrapolation of design methods developed for the wood industry. Nonetheless, buildings having floor and roof diaphragms framed with thin steel joist members and wood sheathing panels are being constructed in North America. To address these shortcomings a test-based research project was carried out at McGill University. The objective was to provide characterization of typical CFS framed / wood-sheathed diaphragm response to in-plane lateral loading, in order to better understand the structural performance, and to provide full force vs. deformation hysteretic parameters for use in subsequent design method development and nonlinear response history analyses of CFS framed structures. This research was a complementary study to the CFS – NEES a project, which involved the dynamic testing of a full-scale two storey CFS framed building. The work detailed herein includes diaphragm test specimens that were based on the floor and roof configurations used in the CFS - NEES Building. The objective was to obtain information regarding the response to loading of the isolated diaphragm systems. The specimens were comprised of oriented strand board (OSB) sheathing screwed to CFS C-Channel joists. Eight 3.66 x 6.1m diaphragm configurations were tested under monotonic and reversed cyclic loading. Design predictions for the shear strength and stiffness of the diaphragm configurations are also included following the provisions of the AISI S213 & AISI S400 Standards.

International Association of Earthquake Engineering2017

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thumb|upright=2|Poumons humains : Le est un organe intrathoracique pair de l'appareil respiratoire, permettant l'échange des gaz vitaux, notamment l'oxygène et le dioxyde de carbone. L'oxygèn

Le cœur est un organe musculaire creux qui assure la circulation sanguine en pompant le sang vers les vaisseaux sanguins et les cavités du corps à travers des contractions rythmiques. L'adjectif c

L’abdomen (du latin, de même sens) est une partie du corps humain ou du corps d'un animal. Chez l'être humain, il est également appelé ventre. Chez l'humain thumb|Abdomen masculin. thumb|

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