PATTERN OF CONTRACTION AND RELAXATION IN TORTOISE VENTRICLE
PATTERN OF CONTRACTION AND RELAXATION IN TORTOISE VENTRICLE
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DOI：
10.1152/ajplegacy.1950.162.1.249
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发表时间：
1950-01-01
影响因子：
--
通讯作者：
GRAY, SW
中科院分区：
文献类型：
--
作者：
GRAY, SW
方法将大规格的伪地理鼠（Graptemys pseudogeagraphica）和拟鼠（Pseudemys troosti）标本，经去髓或冷制动，去除胸甲和心包。用电影摄影机拍摄心脏的腹侧表面，并在双目显微镜下检查所得膜。在搏动期间连续帧上心室的宽度和长度的测量允许心室大小的图形绘图。在所有情况下，心室的宽度开始减少，达到其最小尺寸，并在长度之前恢复到其舒张期大小。这导致了一项努力，将测量结果分成几个部分，以确定肌肉缩短实际上是如何发生的。如图I所示，心室表面上的点是通过直接放置在心室上的多个0.5 mm正方形白色纸确定的。然后拍摄电影胶片，连续帧上成对纸标记之间的距离给出了由被测量的心室特定区域所表示的搏动的图形图像。因此，收缩和松弛的开始时间可以独立地确定一些小的，几乎相等的，局部区域。在搏动开始和结束时叠加胶片可检查纸的正方形相对于心室表面的可能位移。
METHODSLarge specimens of Graptemys pseudogeagraphica and Pseudemys troosti were either pithed or immobilized by cold, and the plastron and pericardium were removed. The ventral surface of the heart was photographed with a motion picture camera and the resulting film examined under a binocular microscope. Measurement of the width and length of the ventricle over successive frames during the beat permitted a graphic plot of the size of the ventricle. In all cases the width of the ventricle began to decrease, reached its least dimension and returned to its diastolic size ahead of the length. This led to an effort to break the measurements into segments to determine how muscle shortening actually takes place. Points on the ventricular surface were established by means of a number of 0.5 mm. squares of white paper placed directly on the ventricle as shown in figure I. Motion picture films were then taken and the distances between pairs of paper markers over successive frames gave a graphic picture of the beat as expressed by the particular region of the ventricle being measured. Thus, the time of onset of contraction and of relaxation could be determined independently for a number of small, almost equal, local areas. Superposition of the film at the beginning and end of the beat provided a check against possible displacement of the squares of paper with respect to the ventricular surface.