Lesson 5 of 12 · 6 min
Lymph (tissue fluid)
NCERT §15.2
Meher's muscle cells are not touching her blood directly: there is a thin wall of capillary in between. So how do O₂ and glucose actually reach them?
The lesson in notes
In short
As blood flows through capillaries in the tissues, water together with small dissolved molecules seeps out into the gaps around the cells. The larger proteins and most formed elements stay inside the vessels.
The fluid that leaves is interstitial fluid or tissue fluid. Its mineral distribution is the same as that of plasma.
All exchange of nutrients, gases and so on between blood and cells happens through this fluid.
The lymphatic system, a network of vessels, collects this fluid and drains it back into the major veins. The fluid inside the lymphatic system is called lymph.
Lymph is colourless and contains specialised lymphocytes responsible for immune responses. It also carries nutrients, hormones and other substances.
Fats are absorbed into lymph through the lacteals in the intestinal villi.
Lymph resembles blood except for its protein content and formed elements.