“等张”和“等渗”在临床上常混为一谈,其实,这种看法并非确切,它们二者之间既有联系,又有差别。所谓等张液,是从生理观点来讲,指与红细胞的张力相等。在等张溶液中红细胞既不肿胀,亦不皱缩,而能维持其原来形状不变。所谓等渗液是指与血浆渗透压近似的溶液,是个理化概念。可以设想把某种溶液用一个半透膜与血浆隔开时,倘若半透膜两侧的溶液渗透压相等,这种溶液便是等渗液。 “Isometric” and “isotonic” are clinically often confused, in fact, this view is not exact, both between them both, there are differences. The so-called isotonic solution, from a physiological point of view, refers to the same tension and red blood cells. In isotonic solution of red blood cells neither swelling, nor shrinking, while maintaining its original shape unchanged. The so-called isotonic solution is similar to the plasma osmotic pressure solution, is a physical and chemical concepts. It can be assumed that when a solution is separated from the plasma by a semipermeable membrane, it is an isotonic solution if the osmotic pressure on both sides of the semipermeable membrane is equal.