Taber Larry A, Zhang Jinmei, Perucchio Renato
Department of Biomedical Engineering, Washington University, Campus Box 1097, St. Louis, MO 63130, USA.
J Biomech Eng. 2007 Jun;129(3):441-9. doi: 10.1115/1.2721076.
Early in development, the heart is a single muscle-wrapped tube without formed valves. Yet survival of the embryo depends on the ability of this tube to pump blood at steadily increasing rates and pressures. Developmental biologists historically have speculated that the heart tube pumps via a peristaltic mechanism, with a wave of contraction propagating from the inflow to the outflow end. Physiological measurements, however, have shown that the flow becomes pulsatile in character quite early in development, before the valves form. Here, we use a computational model for flow though the embryonic heart to explore the pumping mechanism. Results from the model show that endocardial cushions, which are valve primordia arising near the ends of the tube, induce a transition from peristaltic to pulsatile flow. Comparison of numerical results with published experimental data shows reasonably good agreement for various pressure and flow parameters. This study illustrates the interrelationship between form and function in the early embryonic heart.
在发育早期，心脏是一个没有形成瓣膜的单根被肌肉包裹的管子。然而，胚胎的存活取决于这根管子以不断增加的速率和压力泵血的能力。发育生物学家历来推测，心脏管通过蠕动机制泵血，收缩波从流入端传播到流出端。然而，生理学测量表明，在瓣膜形成之前，血流在发育早期就已具有脉动特性。在这里，我们使用一个通过胚胎心脏的血流计算模型来探索泵血机制。模型结果表明，心内膜垫（即管子两端附近出现的瓣膜原基）诱导了从蠕动流到脉动流的转变。数值结果与已发表的实验数据的比较表明，在各种压力和流量参数方面具有相当好的一致性。这项研究说明了早期胚胎心脏中形态与功能之间的相互关系。
