infusion of isotonic saline - addition of isotonic fluid (called also isosmotic volume expansion)
- ECF volume increases, no change in osmolarity of ECF or ICF, no shift of water
- plasma protein concentration and hematocrit decrease because of addition of the fluid;
- RBC do not shrink or swell;
- arterial pressure increases because ECF volume increases;
* diarrhea - loss of isotonic fluid (also called isosmotic volume contraction)
- ECF volume decreases with no change in osmolarity;
- no shift of water between ECF and ICF;
- plasma protein concentration and Haematocrit increase because of the loss of ECF;
- RBC will not shrink or swell;
- arterial blood pressure decreases because ECF volume decreases;