The various types of adult connective tissues in contrast to epithelium have relatively a few cells and a large amount of intercellular substance. But the proportion of these two elements shows variations.
In some type, especially loose connective tissue, cells are quite numerous.
In other types, they are few in number and tissue is composed almost entirely of closely packed fibres.
The type and the nature of the substance in which they are embedded (ground substance) furnish the basis for the subdivision of adult connective tissue into three main groups of connective tissue proper, cartilage and bone.
