Introduction: The internal body environment is a pool of extracellular fluid that fills the spaces present between the cells and tissues. The internal body environment and the volume of extracellular fluid change from time to time. Most of the extracellular fluid is interstitial because it fills the spaces present in between the cells and tissues. As per the changes thatoccur drastically, they create a drastic effect on cellular activities.
Human Biology (MindTap Course List)