Chapter 19, Problem 1CP

Summary Introduction

To review:

The similarities and differences between the blood plasma and interstitial fluid.

Introduction:

Interstitial fluid refers to the fluid that surrounds and bathes the tissue cells in the body of multicellular animals. Plasma is the blood's liquid portion where formed elements such as blood cells are found suspended.

Explanation of Solution

Both plasma and interstitial fluid are found outside the cells and are the major components of the extracellular fluid. Both fluids are of similar composition are and mainly composed of water. Both the fluids lack cells.

The blood plasma and the interstitial fluid differ in the following way:

Blood plasma	Interstitial fluid
Plasma contains higher protein content.	The interstitial fluid contains lower protein content as compared to that in the plasma.
Plasma has a higher amount of dissolved oxygen.	Interstitial fluid contains low amount of dissolved oxygen as it is taken up by the cells.

Conclusion

Thus, the plasma and interstitial fluid are both extracellular fluids with same compositions. The plasma has a higher concentration of protein and dissolved oxygen as compared to interstitial fluid, whereas the interstitial fluid has a higher concentration of carbon dioxide because the cells produce carbon dioxide during energy production and it diffuses out of the cells into the interstitial fluid.