transcellular fluid

Transcellular fluid is the portion of total body water contained within epithelial lined spaces. It is the smallest component of extracellular fluid, which also includes interstitial fluid and plasma. It is often not calculated as a fraction of the extracellular fluid, but it is about 2.5% of the total body water or 5% of extracellular fluid. Examples of this fluid are cerebrospinal fluid, ocular fluid and joint fluid.