Interstitial = Tissue fluid

Characteristics:

• forms 16% of body weight
• formed by filtration of blood plasma into extracellular spaces
• similar composition as a blood plasma but there aren´t no plasma proteins

Function:

• forms enviroment for the cells
• transport of hormones, nutrients, respiratory gasses from blood to the cells and from the cells to the blood

90 % of the tissue fluid returns to the capillaries where it again becomes blood plasma and 10 % forms lymph.