University of Texas Medical Branch

Cell Biology Graduate Program

Look at slide 25 and find the dermis, under the epithelium. The region where it has mostly fibers and fibroblasts is dense irregular connective tissue.  This photo is not from your slide set, but it is representative. Much of the dermis of the skin contains bundles of collagen fibers separated by matrix (seen as clear spaces in the above photo).  The major cell type found is the fibroblast.  These can be seen by their thin black nuclei (oblong) and a thin "stream of cytoplasm" that blends in with the collagen fibers. This is called dense, irregular connective tissue because the fiber bundles are organized in an irregular array.

DENSE REGULAR CONNECTIVE TISSUE

Tendon, which is a strap like body that connects bone to muscle, is made of dense, regular connective tissue.  You can find an example in slide 9. The fibers are oriented in parallel arrays.  Note the thin, dark staining nuclei of the fibroblasts.   Their cytoplasm cannot be distinguished.   How does the arrangement of the fibers help a runner sprint or a kangaroo jump?