人在正常情况下，尿液中的成分主要是水、无机盐、尿素、尿酸等，课本中并没有提到尿的颜色。按课本上讲，尿应该是无色的，但实事上不是。那么尿色是怎么来的？这个问题主要涉及脸红素的代谢。在一般情况下，红细胞不断破坏更新。红细胞在网状内皮系统中被破坏后，放出血红蛋 Under normal circumstances, the composition of urine is mainly water, inorganic salts, urea, uric acid, textbooks did not mention the color of urine. According to the textbook, urine should be colorless, but in fact not. Urine is how come? This problem is mainly related to the metabolism of hyaluronan. Under normal circumstances, red blood cells continue to destroy the update. Red blood cells in the reticuloendothelial system is destroyed, the release of red blood cells