The periodontist will also take a small measuring instrument called a probe and place it between the teeth and gums to determine the depth of those spaces, known as periodontal pockets; this helps the periodontist assess the health of the gums.
The ground substance of connective tissue is different from all of these fluids; it is the liquid medium through which these other fluid exchanges take place.
All connective tissue apart from blood and lymph consists of three main components: fibers (elastic and collagenous fibers), ground substance and cells. (Not all authorities include blood or lymph as connective tissue.) Blood and lymph lack the fiber component.