The function of liquid connective tissue is to transport nutrients, oxygen and other gases, defend the body against pathogens and maintain inflammatory process. This involves lymphatic fluid and blood products, both of which play an important role in homeostasis.
Blood's primary role is to carry respiratory gases and nutrients to the body's cells. As it moves from the arteries to the capillaries, it diffuses through the interstitial spaces that lie between blood vessels and cell walls. To carry waste away, some of this fluid diffuses back in the opposite direction. In addition to transporting gas, it moves leukocytes to areas of infection, allowing phagocytic cells to destroy organisms. Finally, blood also carries B-cells and T-cells, which play an important role in mediating immunity.
Lymphatic fluid acts as a drainage system that allows some of the interstitial fluid to drain away. When there is damage to an area or an infection, the lymphatic system allows more fluid to gather there, which promotes inflammation. Although this is uncomfortable, it does bring more leukocytes to the area, which in turn allows infections to clear. At the same time, the fever that accompanies inflammation prevents bacteria at the site of infection from growing. Inflammation and blood flow to the injured area increase until the body returns to homeostasis.