Water makes up an essential part of our body weight. In our body, water is distributed in two major fluid compartments: the intracellular and extracellular compartments. The intracellular compartment consists of all the fluids inside cells; whereas the extracellular compartment consists of all the fluids outside of cells. The extracellular compartment is further divided into three subcompartments, which are the plasma, the interstitial, and the transcellular subcompartments. Plasma is the liquid part of blood.The interstitial fluid consists of fluids which surrounds the cells, whereas the transcellular compartment includes fluids such as cerebrospinal fluid, which surrounds the brain and spinal cord; lymph, which is a clear fluid that helps circulate immune cells; and peritoneal fluid, which surrounds the organs in the abdominal cavity. About 60% of our body weight is water, 40% of it is intracellular, and 20% is extracellular. This is known as the “ 60-40-20 rule”.
- "Medical Physiology" Elsevier (2016)
- "Physiology" Elsevier (2017)
- "Human Anatomy & Physiology" Pearson (2018)
- "Principles of Anatomy and Physiology" Wiley (2014)
- "The 'third space'--fact or fiction?" Best Pract Res Clin Anaesthesiol (2009)
- "Third-space fluid shift in elderly patients undergoing gastrointestinal surgery: Part 1: Pathophysiological mechanisms" Contemp Nurse (2002)