Anesthesiology, University Hospital Zürich, Rämistrasse 100, Zurich, ZH 8091, Switzerland
Cardiac Surgery, University Hospital of Lausanne, Lausanne, Switzerland.
Eur Heart J. 2014 Sep 7;35(34):2322-32. doi: 10.1093/eurheartj/ehu222. Epub 2014 Jun 10.
A carrier system for gases and nutrients became mandatory when primitive animals grew larger and developed different organs. The first circulatory systems are peristaltic tubes pushing slowly the haemolymph into an open vascular tree without capillaries (worms). Arthropods developed contractile bulges on the abdominal aorta assisted by accessory hearts for wings or legs and by abdominal respiratory motions. Two-chamber heart (atrium and ventricle) appeared among mollusks. Vertebrates have a multi-chamber heart and a closed circulation with capillaries. Their heart has two chambers in fishes, three chambers (two atria and one ventricle) in amphibians and reptiles, and four chambers in birds and mammals. The ventricle of reptiles is partially divided in two cavities by an interventricular septum, leaving only a communication of variable size leading to a variable shunt. Blood pressure increases progressively from 15 mmHg (worms) to 170/70 mmHg (birds) according to the increase in metabolic rate. When systemic pressure exceeds 50 mmHg, a lower pressure system appears for the circulation through gills or lungs in order to improve gas exchange. A four-chamber heart allows a complete separation of systemic and pulmonary circuits. This review describes the circulatory pumping systems used in the different classes of animals, their advantages and failures, and the way they have been modified with evolution.
当原始动物变得更大并发展出不同的器官时，气体和营养物质的载体系统就变得必不可少了。最初的循环系统是蠕动管，缓慢地将血淋巴推入没有毛细血管的开放血管树（蠕虫）。节肢动物在腹主动脉上发展出可收缩的隆起，由辅助翅膀或腿部的心脏和腹部呼吸运动来协助。双心房心脏（心房和心室）出现在软体动物中。脊椎动物有一个多腔心脏和一个带有毛细血管的封闭循环。鱼类的心脏有两个腔室，两栖动物和爬行动物的心脏有三个腔室（两个心房和一个心室），鸟类和哺乳动物的心脏有四个腔室。爬行动物的心室通过室间隔部分分为两个腔室，只留下一个可变大小的连通口，导致可变的分流。根据代谢率的增加，血压从 15mmHg（蠕虫）逐渐升高到 170/70mmHg（鸟类）。当体循环压力超过 50mmHg 时，为了改善气体交换，出现了一个较低压力系统，用于通过鳃或肺循环。四腔心脏允许系统和肺循环完全分离。本文综述了不同类群动物中使用的循环泵送系统，及其优点和缺陷，以及它们在进化过程中是如何被改变的。
