出典:Wikipedia
出典:『Wikipedia』 (2011/06/06 07:33 UTC 版)
A countercurrent multiplier system is a system that expends energy to create a concentration gradient. For example, it can refer to the process underlying the process of urine concentration, that is, the production of hyperosmotic urine by the mammalian kidney. The ability to concentrate urine is also present in birds, but involves another mechanism which is not comparable.