The fluid inside your eyeball is intraocular fluid (sometimes called vitreous humour). We also have slippery serous fluids in our abdominal and chest cavities, known as peritoneal fluid and pleural fluid, respectively. Sinovial fluids are the slippery fluids contained within the sinovial joints such as the knee, elbow, and between the tibia and femur. For example, CSF surrounds your brain and spinal cord and it’s contained in your skull and your spinal column. Transcellular fluids are ECF that are contained in specific anatomical areas of the body, within epithelial lined spaces. Transcellular fluid: Often not calculated as a fraction of the extracellular fluid, but it is about 2.5% of TBW. Now to make things slightly more complicated, there’s really three types of ECF: E comes before I in the alphabet, so E is 1/3rd and I is 2/3rd. Mnemonic to help you remember which is 1/3rd and 2/3rd: ECF and ICF. ECF is also known as interstitial fluid because it’s the fluid in between the cells. Intracellular Fluid (ICF): The amount of water that’s inside our cells accounts for 2/3rds of our TBW.Įxtracellular Fluid (ECF): The amount of water that surrounds our cells accounts for 1/3 of our TBW. TBW: 0.6 x 68.9kg is 41kg which means we have 41L TBW. So anyway, the answer is very close to that. If we divide 2 into 150, that would be 75kg. Normally you would have used your calculator to do this but I beg you estimate what the right number should be. Why is body weight expressed in kilograms? Because the metric system is very clever: One liter of fluid weighs one kilogram. The first thing we need to do is convert pounds to kilograms. So, sometimes we need to estimate what is the total amount of water a person is made of. You know water is the major thing that living things are made of and as a nurse, you’re going to need to make sure your patients hydration levels are appropriate.

Calculation of body fluid compartments