Tissue fluid (lymph):

The fluid present in the spaces between calls in tissues is called tissue fluid or lymph. Exchange of materials between the blood & tissue cells occurs through this fluid. Tissue fluid contains water & dissolved material (white cells, electrolytes, glucose, fatty acids, amino acids, oxygen, Co₂ & glycerol).

Functions of lymph:

• It acts as ‘middle man’.  Helps in exchange of material between tissues & blood.
• Keeps the tissue cells moist.
• Lymph gives Co₂, waste materials to blood & takes oxygen & food materials.
• Transport digested fats and fats soluble vitamins, etc.
• Storage of immunologically competent cells called lymphocytes.
• It also carries fats and lipids absorbed from small intestine to the blood in the form of chylo-microns.

Difference between lymph and blood:

 

Blood	Lymph
(1) It is red fluid connective tissue. (2) It flows in blood vessels. (3) It contains plasma, RBCs, WBCs & platelets. (4) It has hemoglobin. (5) It transports materials from one organ to another in body.	(1) It is colorless fluid connective tissue. (2) It flows in tissue space. (3) It contains plasma & WBCs.   (4) It has no hemoglobin. (5) It exchanges materials between blood & tissues.