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 the body's defense against infectious organisms and other invaders. Through a series of steps called the immune response, the immune system attacks organisms and substances that invade body systems and cause disease. The immune system is made up of a network of cells, tissues, and organs that work together to protect the body. One of the important cells involved are white blood cells, also called leukocytes, which come in two basic types that combine to seek out and destroy disease-causing organisms or substances.