They are graphs that tell you the osmolarity and volume changes of body fluids.
X axis represents volume.
Y axis represents solute concentration.
Total body water = 2/3 ICF (Intracellular fluid) + 1/3 ECF (Extracellular fluid)
All volume disturbances originate in the ECF compartment.
Changes in ICF are in response to changes in ECF.
How to make the graph in your head -
Step 1. Figure out what happens to the osmolarity and volume in the ECF compartment (ECF is the smaller compartment)
Step 2. Think how is ICF affected?
Let's review some examples to make sure we understand the concept!