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.
Connective tissue is composed primarily of two elements: cells and a matrix. The types of cells found in connective tissue vary depending on the type of tissue they support. For example, red and white blood cells are found in blood, which is a fluid connective tissue. Adipocytes are fat cells found in adipose tissue, or fat. And fibroblasts are cells found in large quantities in many different types of connective tissues. The matrix can be thought of as the substance in which the cells are embedded. The matrix can be fluid, semifluid, gelatinous, or ground substance and protein fibers.