Lymphatic vessels transport fluids that have been filtered from the cardiovascular system back into the blood, thus maintaining blood volume. Lymphatic Vessels A. Formation of Lymph 1. The amount of fluid reabsorbed is less than the amount filtered, by about 3 liters per day. Lymph vessels begin as blind-ended capillaries that are highly permeable.
Macrophages reside on the protein fibers of the network.
Interferons also activate macrophages and mobilize NK cells.