What is the Difference Between Plasma and Interstitial Fluid?

Plasma and interstitial fluid are both extracellular fluids found in the body, but they have distinct differences in terms of composition and properties. Here are the main differences between the two:

1. Location: Plasma is found within blood vessels, while interstitial fluid is present outside the blood vessels in the tissue.
2. Composition: Plasma is a straw-colored fluid that makes up more than half of the blood and contains 90-92% water and 6-8% proteins, including albumin, fibrinogen, and globulins. Interstitial fluid, on the other hand, is a fluid that surrounds and bathes all body cells.
3. Protein Concentration: Plasma has a higher protein concentration compared to interstitial fluid.
4. Ion Concentrations: Plasma has different ion concentrations compared to interstitial fluid.
5. Carbon Dioxide and Oxygen Content: Plasma has less dissolved carbon dioxide, while interstitial fluid has more carbon dioxide content. Plasma has more dissolved oxygen, whereas interstitial fluid has less dissolved oxygen.
6. Major Roles: Plasma's major role is to aid in blood coagulation during trauma or injury. Interstitial fluid's major role is the exchange of nutrients and gases between cells and blood.

Comparative Table: Plasma vs Interstitial Fluid

The main differences between plasma and interstitial fluid can be summarized in the following table:

Plasma is the liquid component of blood and has a higher protein concentration compared to interstitial fluid. It contains blood cells, proteins, electrolytes, nutrients, gases, and wastes. Interstitial fluid, on the other hand, is the fluid that surrounds cells in tissues and has a lower protein concentration than plasma. It plays a crucial role in the exchange of gases, nutrients, and waste materials between capillaries and cells.