The concentration of proteins is much higher in the plasma than in the interstitial fluid because proteins are too large to pass through the capillary endothelium.

Question

Quizplus · Accepted Answer

The capillary endothelium has small pores that allow small molecules such as ions and nutrients to pass through, but larger molecules such as proteins are restricted. Therefore, proteins tend to remain in the plasma and do not leak into the interstitial fluid, resulting in a higher concentration of proteins in the plasma.

The Concentration of Proteins Is Much Higher in the Plasma