Plasma vs Interstitial Fluid
Water is the main component of body fluids. The body water can be found mostly in two major compartments called intracellular fluid and extracellular fluid. Intracellular fluid can be found within the cells of the body. The extracellular fluid can be found outside of the cells. Blood plasma and interstitial fluid are the major compartments of extracellular fluid.
The extracellular fluid found within the vascular system is the blood plasma. Blood cells and platelets are suspended in this blood plasma. The blood plasma contains many dissolved substances like oxygen, carbon dioxide, salts, amino acids, fatty acids, hormones, and plasma proteins. A tiny difference in concentrations of cations and anions can be found in plasma than interstitial fluid. Plasma acts as a protein reserve of the human body. Also, while keeping the electrolytic balance it helps to protect the body from infections.
The body cells are surrounded by the interstitial fluid. Generally due to the difficulty of separation, interstitial fluid and lymph are considered as a single component. The interstitial fluid can be considered as ultra filtrate of plasma. It is also known as tissue fluid, which transports nutrients from the blood to the cells, and carbon dioxide and other wastes back to the blood from the cells.
What is the difference between Plasma and Interstitial Fluid?
• Plasma can be found within the vascular system of the body while body cells are surrounded by interstitial fluid.
• The protein concentration in the plasma is higher than in interstitial fluid.
• Hormones and plasma proteins exist within the plasma, whereas some hormones and proteins secreted by cells can be seen in interstitial fluid.
• Erythrocytes, leucocytes, and platelets are the major cell types found in blood plasma. Unlike in plasma, only some leucocytes can be found in interstitial fluid.
• The glucose concentration is higher in plasma than interstitial fluid.
• Amino acid and oxygen concentration are also higher in plasma than in interstitial fluid.
• One fourth of the extracellular fluid is composed of water in plasma. The remaining three fourth is composed of water in interstitial fluid and lymph.
• The concentrations of diffusible cations are higher in plasma than that of interstitial fluid.
• The diffusible anion concentrations are lower in plasma than interstitial fluid.
• The concentrations of bound and free Ca2+ and Mg2+ are higher in plasma than in interstitial fluid.