I am confused about how increased potassium intake lowers blood volume. I understand that K+ is the primary intracellular cation, and Na+ is the primary extracellular one. I also know that the Na-K pump ejects 3 Na+ from the cell for every 2 K+ it brings into the cell. My book physiology book is very vague about how this works. Anyone have an explicit explination for how this works?