Question

Because of the high amount of permeability that occurs between the plasma and interstitial fluid, their compositions are virtually equal and the same. What are the 2 main differences between them?

Answer 1

The two main differences between plasma and interstitial fluid are the higher concentration of proteins in plasma and the presence of red blood cells and platelets in plasma, which are absent in interstitial fluid.

Step-by-step explanation:

While plasma and interstitial fluid have similar compositions due to their permeability to many substances, they differ in two main aspects. The first difference is the presence of a higher concentration of proteins in plasma. Because the capillary walls are not permeable to large molecules, plasma proteins do not typically pass into the interstitial fluid. The second difference is the presence of red blood cells and platelets in plasma, which are too large to cross the capillary wall and do not exist in the interstitial compartment.

The plasma carries materials such as blood cells, proteins, electrolytes, nutrients, gases, and wastes through the blood vessels. In contrast, the interstitial fluid bathes the cells, providing them with nutrients and a means to remove waste, but without the cellular components and higher protein levels found in plasma.