Question

1. Recall that the osmolarity of the gastric fluid, plasma, interstitial fluid, and intracellular fluid is approximately 280mOsm to 300mOsm. Why is it important for these compartments to be relatively isotonic?

Answer 1

Ans:- All this compartment need to be isotonic so that there is little or no exchange of water between this fluids (gastric juice ,plasma) and intracellular fluid.

Because suppose if interistitial fluid osmolarity is higher then intracellular osmolarity the water will move out of the cell in the interistitial fluid causing edema .

If osmolarity of intetsinal juices and gastric juice is high then it will cause secretion of water into the lumen of git causing diarrhoea.

Similarly RBC will also shrink and stop functioning if osmolarity of plasma will be higher.

so to maintain a constant homeostasis of body . All this fluids have same osmolarity.