When plasma passes out of capillary walls into the surrounding tissues it is called interstitial fluid and provides the necessary nourishing substances for cellular life. This interstitial fluid contains proteins that help draw fluid across the capillary wall. Here, it will be drawn to the hyaluronic acid content of the glycosaminoglycans gel, aiding the support of collagen, elastin fibrils and the many other cells that reside in the dermis. Some fluid will move up through the dermal/epidermal junction towards the epidermis to aid the hydration of the epidermal cells and become part of the trans-epidermal water loss (TWEL) of the epidermis. After bathing the cells, 90-98% of the interstitial fluid re-enters the capillaries, returning to the heart through the veins. The other 2-10% returns via the lymph capillary system, which is a system of dead-end capillaries that extend into most tissues, paralleling the blood capillaries. Lymph fluid is the nourishing fluid of the cells. The lymphatic system is not only a reservoir of organic fluids and defense system against microbial invasion. Lymph fluid is the healer of wounds, the builder of tissues and regenerator for the body.