Organization and Matrix

Key concept

The embryonic dermis consists of a syncytium of interconnected cells suspended in a watery matrix of hyaluronic acid. The cells differentiate into fibroblasts which replace the primordial dermis with a cell-poor dense fibrous matrix of collagen, elastin, and dermatan sulfate. The fibrillar components of the dermis continue to develop well after birth.

Bullet Summary

• 6 Weeks: Cellular primordial dermis
• 9 Weeks: Transition to fibrous matrix begins
• 11 Weeks: Dermal-subcutaneous boundary forms
• 16 Weeks: Dermis demarcates into papillary and reticular regions
• 14-17 Weeks: Elastic fibers form
• 25 Weeks: Interlacing bundles of collagen appear
• 26+ Weeks: Crosslinking of collagen occurs

To study the organization and matrix over time click on one of the buttons below:

Week 6
Week 9
Week 11
Week 16
Weeks 14-17
Week 25
Weeks 26 and beyond