Swain D P
Wellness Institute and Research Center, Old Dominion University, Norfolk, Virginia 23529-0196, USA.
Adv Physiol Educ. 2000 Dec;24(1):43-50. doi: 10.1152/advances.2000.24.1.43.
The cardiovascular system is a complex arrangement of hydraulic, yet living, components. The complexity of this system may make it difficult for students to see the "forest" instead of the "trees." To better explain the dynamics of cardiovascular function and control, an analogy has been drawn to the operation of a city water supply. In cities that use a water tower, fresh water is pumped up into the tower from a river or other source. The tower serves as a pressure reservoir for providing water to homes through a largely parallel arrangement of distribution pipes. Local homeowners control their own water usage through faucets, whereas the city maintains water pressure by monitoring the level in the tower. Key analogous points with the cardiovascular system are the heart as the city pump, the aorta as the water tower, arteries as parallel distribution pipes, and arterioles as faucets. Baroreceptor reflex control is discussed as well as such features as the capacitance role of veins, the skeletal muscle pump, and the competition between locally mediated vasodilation and sympathetically mediated vasoconstriction. Subjective student and peer evaluations have indicated that this analogy is effective in improving student comprehension of the cardiovascular system.
心血管系统是由液压但仍具生命的组件构成的复杂组合。该系统的复杂性可能使学生难以看清“森林”而非“树木”。为了更好地解释心血管功能和控制的动态过程，人们将其与城市供水系统的运作进行了类比。在使用水塔的城市中，淡水从河流或其他水源被泵入水塔。水塔作为压力蓄水池，通过大致平行排列的配水管向家庭供水。当地居民通过水龙头控制自己的用水，而城市则通过监测水塔中的水位来维持水压。与心血管系统的关键类比点包括：心脏如同城市水泵，主动脉如同水塔，动脉如同平行的配水管，小动脉如同水龙头。文中还讨论了压力感受器反射控制以及静脉的容量作用、骨骼肌泵，以及局部介导的血管舒张与交感神经介导的血管收缩之间的竞争等特征。学生和同行的主观评价表明，这种类比在提高学生对心血管系统的理解方面是有效的。
