Victor S, Nayak V M, Rajasingh R
Tex Heart Inst J. 1999;26(3):168-75; discussion 175-6.
We studied the evolution of ventricles by macroscopic examination of the hearts of marine cartilaginous and bony fish, and by angiocardiography and gross examination of the hearts of air-breathing freshwater fish, frogs, turtles, snakes, and crocodiles. A right-sided, thin-walled ventricular lumen is seen in the fish, frog, turtle, and snake. In fish, there is external symmetry of the ventricle, internal asymmetry, and a thick-walled left ventricle with a small inlet chamber. In animals such as frogs, turtles, and snakes, the left ventricle exists as a small-cavitied contractile sponge. The high pressure generated by this spongy left ventricle, the direction of the jet, the ventriculoarterial orientation, and the bulbar spiral valve in the frog help to separate the systemic and pulmonary circulations. In the crocodile, the right aorta is connected to the left ventricle, and there is a complete interventricular septum and an improved left ventricular lumen when compared with turtles and snakes. The heart is housed in a rigid pericardial cavity in the shark, possibly to protect it from changing underwater pressure. The pericardial cavity in various species permits movements of the heart-which vary depending on the ventriculoarterial orientation and need for the ventricle to generate torque or spin on the ejected blood- that favor run-off into the appropriate arteries and their branches. In the lower species, it is not clear whether the spongy myocardium contributes to myocardial oxygenation. In human beings, spongy myocardium constitutes a rare form of congenital heart disease.
我们通过对海洋软骨鱼类和硬骨鱼类心脏的宏观检查，以及对呼吸空气的淡水鱼、青蛙、乌龟、蛇和鳄鱼心脏的血管造影和大体检查，研究了心室的进化。在鱼类、青蛙、乌龟和蛇中可以看到右侧薄壁的心室腔。在鱼类中，心室外部对称，内部不对称，左心室壁厚且有一个小的入口腔。在青蛙、乌龟和蛇等动物中，左心室以小腔室的收缩性海绵体形式存在。青蛙体内这种海绵状左心室产生的高压、射流方向、心室动脉方向以及球部螺旋瓣有助于分离体循环和肺循环。在鳄鱼中，右主动脉与左心室相连，与乌龟和蛇相比，有完整的室间隔和改善的左心室腔。鲨鱼的心脏位于坚硬的心包腔内，可能是为了保护它免受水下压力变化的影响。不同物种的心包腔允许心脏运动——这些运动因心室动脉方向以及心室对射出的血液产生扭矩或旋转的需求而异——有利于血液流入适当的动脉及其分支。在较低等的物种中，尚不清楚海绵状心肌是否有助于心肌的氧合作用。在人类中，海绵状心肌是一种罕见的先天性心脏病形式。
