Fan Yanhua, Gregersen Hans, Kassab Ghassan S
Institute of Experimental Clinical Research, Skejby Hospital, Aarhus, Denmark.
Biomed Eng Online. 2004 Nov 1;3(1):40. doi: 10.1186/1475-925X-3-40.
The function of esophagus is to move food by peristaltic motion which is the result of the interaction of the tissue forces in the esophageal wall and the hydrodynamic forces in the food bolus. The structure of the esophagus is layered. In this paper, the esophagus is treated as a two-layered structure consisting of an inner collagen-rich submucosa layer and an outer muscle layer. We developed a model and experimental setup for determination of elastic moduli in the two layers in circumferential direction and related the measured elastic modulus of the intact esophagus to the elastic modulus computed from the elastic moduli of the two layers.
Inflation experiments were done at in vivo length and pressure-diameters relations were recorded for the rat esophagus. Furthermore, the zero-stress state was taken into consideration.
The radius and the strain increased as function of pressure in the intact as well as in the individual layers of the esophagus. At pressures higher than 1.5 cmH2O the muscle layer had a larger radius and strain than the mucosa-submucosa layer. The strain for the intact esophagus and for the muscle layer was negative at low pressures indicating the presence of residual strains in the tissue. The stress-strain curve for the submucosa-mucosa layer was shifted to the left of the curves for the muscle layer and for the intact esophagus at strains higher than 0.3. The tangent modulus was highest in the submucosa-mucosa layer, indicating that the submucosa-mucosa has the highest stiffness. A good agreement was found between the measured elastic modulus of the intact esophagus and the elastic modulus computed from the elastic moduli of the two separated layers.
食管的功能是通过蠕动运动推动食物，这是食管壁组织力与食团流体动力相互作用的结果。食管结构呈分层状。在本文中，食管被视为由富含胶原蛋白的内层黏膜下层和外层肌肉层组成的双层结构。我们开发了一个模型和实验装置，用于测定两层在圆周方向的弹性模量，并将完整食管的测量弹性模量与由两层弹性模量计算得出的弹性模量相关联。
在大鼠食管的体内长度下进行充气实验，并记录压力 - 直径关系。此外，还考虑了零应力状态。
完整食管及其各层的半径和应变均随压力增加而增大。在压力高于1.5 cmH₂O时，肌肉层的半径和应变大于黏膜 - 黏膜下层。完整食管和肌肉层在低压下的应变均为负，表明组织中存在残余应变。在应变高于0.3时，黏膜下层 - 黏膜层的应力 - 应变曲线向肌肉层和完整食管曲线的左侧偏移。黏膜下层 - 黏膜层的切线模量最高，表明黏膜下层 - 黏膜层具有最高的刚度。完整食管的测量弹性模量与由两个分离层的弹性模量计算得出的弹性模量之间发现了良好的一致性。
