Is it true that substances are carried from the blood in capillaries to tissues in a liquid called tissue fluid? What is the extracellular fluid in most tissues is called? What is a tissue fluid?   Tissue fluid is the the fluid that surrounds the bodies cells, or technically it bathes the cells in the body or cleans them.
The most important function of immune system is to defend the body from different disease causing pathogens. Whenever there is pathology in human body, immune system is activated to protect the vital tissues from harm.
The immune system is a collection of cells found in the blood and in tissues throughout the body that help to protect the body from infection. These cells perform a variety of nonspecific and specific functions to defend the body against harmful particles (e.g. , bacteria, viruses, toxins, and cancerous cells).