Key Facts
- Friction ridge skin consists of ridges and furrows, anchored in the dermis by primary and secondary ridges.
- Primary and secondary ridges provide support and strength to the friction ridge skin.
- Sweat glands are connected to primary ridges and are anchored in the dermis or hypodermis.
- The persistence of friction ridge skin aids in individual identification due to its unique structure.
- Variations in friction ridge impressions arise from the skin's flexibility and its ability to distribute pressure.
The ridges and furrows on the surface of the friction ridge skin are firmly rooted in the dermis by primary ridges (under-the-surface ridges) and secondary ridges (under the valleys). The primary and secondary ridges are interlocked with the dermis to provide support and strength to the friction ridge skin. Additionally, sweat glands extend from the primary ridges and are anchored in the dermis or hypodermis.
The persistence of the friction ridge skin is explained by the physical attachments of the skin and by the regulated replacement of cells lost at the surface of the skin. The persistent nature of the friction ridge skin makes it an ideal anthropological feature to use as a means of identifying individuals. The structure of the skin also provides a mechanism through which to describe distortion. Variation in the appearance of friction ridge impressions is due to the flexibility of the skin. Understanding that the skin distributes pressure into the more flexible furrows offers valuable insight during the analysis of friction ridge impressions.
