Integration and control of circulatory function.
Integration and control of circulatory function.
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循环功能的整合和控制。
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
DeClue Jw
中科院分区：
文献类型：
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作者：
A. C. Guyton;A. W. Cowley;D. Young;T. Coleman;J. Hall;DeClue Jw
在本章中，我们特别强调了循环的内在控制，例如控制局部血流的自动调节机制、心输出量的自动控制、动脉压的长期控制、血容量的长期控制以及液体在循环和间质空间之间的自动分配。强调这些机制的原因有几个：首先，许多实验现在已经表明，内在机制可以提供高度稳定的长期循环控制。其次，神经和荷尔蒙控制的价值在过去可能被过分强调了。第三，内在控制具有特殊的复杂性——例如非线性、响应延迟和其他效应——这使得这些控制变得难以理解；可能正是这些困难导致了它们的重视不够。然而，我们并不是想从神经和荷尔蒙系统中获取它们在循环控制中的真正重要性。例如，内在机制几乎没有急性动脉压控制的能力（仅用于长期控制），并且它们没有提供使动物摄入水和电解质所需的驱动的机制。这些都需要神经控制。此外，神经反射对于增强血容量控制和心脏泵血控制的有效性也很重要。在激素机制中，当血压低于正常值时，肾素-血管紧张素系统可以通过在外周血管中引起血管收缩反应来提供适度的动脉压控制。然而，这个系统似乎还有更重要的肾功能，直接作用于肾脏导致液体潴留；这反过来又增加了体液量，从而增加了动脉压。最后，ADH 和醛固酮在控制血容量中的作用可能被过分强调了。另一方面，临床经验和实验研究都开始证明口渴/ADH 系统可能是迄今为止我们控制细胞外液钠离子浓度的最有效机制。另一方面，醛固酮机制似乎是我们维持正常细胞外液钾浓度的主要控制系统。
In this chapter we have emphasized especially the intrinsic controls of the circulation, such as the autoregulation mechanism for control of local blood flow, automatic control of cardiac output, long-term control of arterial pressure, long-term control of blood volume, and automatic distribution of fluids between the circulation and the interstitial spaces. The reasons for emphasizing these mechanisms are several: first, many experiments have now shown that the intrinsic mechanisms can provide highly stable long-term control of the circulation. Second, the value of the nervous and hormonal controls have probably been greatly overemphasized in the past. And, third, there are special complexities of the intrinsic controls--such as nonlinearities, delay in responses, and other effects--that have made these difficult to understand; it is probably these difficulties that have led to their underemphasis. However, we have not meant to take from the nervous and hormonal systems their true importance in circulatory control. For instance, intrinsic mechanisms have almost no capability for acute arterial pressure control (only for long-term control), and they have no mechanism for providing the drive necessary to make the animal ingest water and electrolytes. These require the nervous controls. Also, nervous reflexes are important in enhancing the effectiveness of blood volume control and control of cardiac pumping. Among the hormonal mechanisms, the renin-angiotensin system can provide a modest degree of arterial pressure control when the pressure falls below normal by eliciting a vasoconstrictor response in the peripheral blood vessels. However, this system seems to have an even more important renal function, a direct effect on kidneys to cause fluid retention; this in turn increases the body fluid volume and in this way increases the arterial pressure. Finally, the roles of ADH and aldosterone in the control of blood volume have probably been greatly overemphasized. On the other hand, both clinical experience and experimental studies are beginning to demonstrate that the thirst/ADH system is probably by far the most potent mechanism that we have for control of extracellular fluid sodium ion concentration. On the other hand, the aldosterone mechanism seems to be our primary control system for maintaining a normal extracellular fluid concentration of potassium.