Body Fluid Compartments

What are areas of the body that come into contact with the external environment?

Our skin as well as the lining of our body tracts come into contact with our external environment; that includes our respiratory, urinary, reproductive and digestive systems.

What is our internal environment made up of?

Our internal environment is made up of various kinds of bodily fluids, including extracellular fluids, intercellular fluid, interstitial fluid, and plasma.

What elements are abundant in ICF (intracellular fluid)?

ICF is high in K+ which the cell lets in and proteins that are stuck inside the cell.

What elements are abundant in ECF (extracellular fluid)?

There is more Na+ and Cl- in ECF, because cells like to keep salt out of the ICF. There is also a lot of plasma in ECF.