Cartilage and Bone. Fluid connective tissue types, of which there are only two, are important in transport and body defense. Most connective tissues are variants of the second group, connective tissue proper where cells are interspersed among protein fibers in a fluid-filled matrix.xtracellular spaces in connective tissues are therefore more abundant and contain vessels. In connective tissues, the extracellular space is termed the extracellular matrix because products of specialized cells accumulate here.