The cellular components of connective tissue are relatively sparse and often embedded in, and separated from, other cells by the extracellular matrix.
Connective tissue varies in the relative proportions of cells and extracellular matrix.
Dense connective tissue contains very few cells and a large amounts of fibers organized into regular bundles. This type of connective tissue is found mainly in tendons, ligaments, and aponeuroses. Loose connective tissue contains a greater proportion of cells and the extracellular matrix is not as well organized. Loose connective tissue is frequently found just below sheets of epithelial tissue and around blood vessels. This is sometimes referred to as fatty connective tissue .