Dense Connective Tissue Proper
The two types of dense connective tissue are different in the arrangement of their collagen fibers. Both have their collagen fibers packed tightly together. However, in dense regular the collage fibers are arranged in parallel sheets/rows, while in dense irregular the collagen fibers are found in patches that are arranged in random different directions.
dense regular connective tissue
Dense regular connective tissue is found in our ligaments, tendons, and aponeuroses (connecting two muscles together). Because the collagen fibers run in parallel rows (all in the same direction), dense regular connective tissue can withstand a tremendous pulling forces if you pull on it from both ends. This is important for our joints and allows enormous range of motion. However, this tissue is easily pulled apart, or torn, if it is pulled on from the sides. This is why joint injury to the ligament/tendon is so common in sports (the tendon was pulled on from the sides and the strands pulled apart). The cells visible in dense regular connective tissue are fibroblasts, which produce the collagen protein fibers. Figure 1 shows dense regular connective tissue with and without an illustration overlay. In the microscope image, collagen fibers appear pink, and in the illustration overlay collagen fibers are drawn in blue.
Table 1: Dense regular connective tissue
| Tissue Type | Dense Regular Connective Tissue |
|---|---|
| General Description | Densely packed parallel collagen fibers with fibroblast with flattened nuclei sitting between the fibers |
| Location | Tendons, ligaments, and aponeurosis |
| Function | Provides strength and resistance to pulling forces in one direction |
| Helpful Hints | Look for packed fibers running in one direction, fibers may have a slightly wavy appearance |
Figure 1: Dense regular connective tissue with and without illustration overlay
Check out our YouTube video to help you understand dense regular connective tissue:
YouTube Video – Dense Regular Connective Tissue
dense IRregular connective tissue
Dense irregular connective tissue is found in the dermis of our skin. Because the collagen fibers are arranged in short sheets arranged different directions, dense irregular connective tissue can withstand pulling forces from lots of different directions. This is important for our skin, which must withstand all the twisting, pulling, and pushing caused by our body movements. The cells visible in dense regular connective tissue are fibroblasts, which produce the collagen protein fibers. Dense irregular connective tissue resembles a patch-work quilt. Figure 2 shows dense irregular connective tissue with and without an illustration overlay. In the microscope image, collagen fibers appear pink, and in the illustration overlay collagen fibers are drawn in blue.
Table 2: Dense irregular connective tissue
| Tissue Type | Dense Irregular Connective Tissue |
|---|---|
| General Description | Densely packed collagen fibers running in multiple directions with fibroblast with flattened nuclei sitting between the fibers |
| Location | Reticular layer of the skin, submucosa of the digestive tract, and fibrous capsules of organs such as the kidney |
| Function | Provides strength and resistance to pulling forces in many directions |
| Helpful Hints | Look for patches of thick collagen fibers running in multiple directions |
Figure 2: Dense irregular connective tissue with and without illustration overlay
Check out our YouTube video to help you understand dense irregular connective tissue:
YouTube Video – Dense Irregular Connective Tissue
Chapter Illustrations By:
Soma Mukhopadhyay, Ph.D.
Collagen is a fibrous protein that has many structural types
connective tissue connections between to muscle groups
cell type found in connective tissue that actively produces the proteins in the extracellular matrix
the deepest region of the skin (underlying the epidermis), consisting of two layers: the papillary layer is areolar connective tissue and the reticular layer is dense irregular connective tissue
