The zero-stress state of rat veins and vena cava.
The zero-stress state of rat veins and vena cava.
复制标题
大鼠静脉和腔静脉的零应力状态。
DOI：
10.1115/1.2894083
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Fung,YC
中科院分区：
文献类型：
--
作者：
Xie,JP;Liu,SQ;Yang,RF;Fung,YC
静脉的零应力状态与动脉的零应力状态一样，不是封闭的圆柱形管，而是一系列横截面为开放扇区的节段。每个扇区的开口角被定义为将内壁的中点连接到内壁的尖端的两个半径之间所对的角。提供了大鼠静脉和腔静脉的张开角数据（平均值±标准差）。对于上级腔静脉和锁骨下静脉、颈静脉、面静脉、肾静脉、髂总静脉、隐静脉和足底静脉，开口角度在25 °至75 °的范围内变化。然而，下腔静脉（在心脏下方）具有非圆形、非轴对称的横截面、弯曲的轴线和其“直径”的快速纵向变化;其零应力状态不是圆形扇区;但张开角仍然是一个有用的表征。内腔静脉的平均开口角在胸部中在40至150度的范围内变化，在腹部中在75至130度的范围内变化，其中较大的值发生在每个部分的中间。在体外，腔静脉从稳态到无负荷状态有相当大的长度、直径减小和壁增厚。在物理上，零应力状态是血管应力分析的基础。开口角的变化是表征由于物理应力或化学环境的变化而导致的血管壁的任何不均匀重塑的方便参数。零应力状态的改变影响了血管的顺应性和顺应性，它们的压力-容积和压力-流量关系，瀑布现象，以及如果稳态应力改变时血管平滑肌的张力。
The zero-stress state of a vein is, like that of an artery, not a closed cylindrical tube, but is a series of segments whose cross-sections are open sectors. An opening angle of each sector is defined as the angle subtended between two radii joining the midpoint of the inner wall to the tips of the inner wall. Data on the opening angles (mean ± standard deviation) of the veins and vena cava of the rat are presented. For the superior vena cava and subclavian, jugular, facial, renal, common iliac, saphenous, and plantar veins, the opening angle varies in the range of 25 to 75 deg. The inferior vena cava (below the heart), however, has noncircular, nonaxisymmetric cross-sections, a curved axis, and a rapid longitudinal variation of its “diameter;” its zero-stress state is not circular sectors; but the opening angle is still a useful characterization. The mean opening angle of the interior vena cava varies in the range of 40 to 150 deg in the thoracic portion, and 75 to 130 deg in the abdominal portion, with the larger values occurring about the middle of each portion. There are considerable length, diameter reductions, and wall thickening of the vena cava from the homeostatic state to the no-load state in vitro. Physically, the zero-stress state is the basis of the stress analysis of blood vessels. The change of opening angle is a convenient parameter to characterize any nonuniform remodeling of the vessel wall due to changes in physical stress or chemical environment. Change of zerostress state influences the compliance and collapsibility of the viens, their pressure-volume and pressure-flow relationships, the waterfall phenomenon, and the tone in the vascular smooth muscles if the homeostatic stress is changed.