In humans, the normal glucose concentration of extracellular fluid that is regulated by homeostasis is approximately 5 mM. The pH of extracellular fluid is tightly regulated by buffers around 7.4. The volume of extracellular fluid is typically 15 L (i.e. 12 L is interstitial fluid and 3 L is plasma).
Word origin: L, comb. form of extrā (adv. and prep.), outside (of), without. + NL cellulāris, equiv. to cellul(a), live cell.