Friction Ridge Skin Morphology

[Boyd Baumgartner]

I've been reading up on some of the articles here on CLPEX and other sites, and am trying to understand the relationship between some structures. I'm in need of some clarification when it comes to the papillary ridges, dermal pegs, primary and secondary ridges as they relate to the dermal morphology and correllate to the epidermal morphology.

For instance, I hear the term secondary ridge used in the sense that it corresponds to the furrows in the fingerprint pattern, however is a secondary ridge really a dermal furrow, as I see no upthrusts in the papillary ridges at these points.

Much appreciated.

Boyd

[Kasey Wertheim]

Boyd,

The structure of skin was one of the more complex areas of study during my training. It took me quite a while to grasp the concept due to what appears to be contradictory drawings in different publications. I'll e-mail you the 65-page JFI article that Alice and I wrote on the topic if you don't have access or haven't come across it.

But without getting into that much detail, there are two dermal ridges for every epidermal ridge. What you define as a "ridge" in the derims, however, is the interesting part... "primary" and "secondary" refer to protrusions of epidermis that go downward into the dermis, so in this sense they are "negative" ridges when compared to the surface ridges. The primary ridge is the mirror image of a surface ridge (surface ridge protrudes upward and the primary ridge protrudes downward); the secondary ridge is a shadow of a surface furrow (they both protrude downward) The dermal papilli become what is left over from these protrusions into the dermis, so in essence they are the "furrows" of the reverse primary and secondary ridges.

It would help to discuss this while looking at a cross-section of skin; if you want me to post an image with numeric reference points, I will be happy to. Just say the word.

-Kasey

[Michele]

Kasey,

I'd like to see it.

[Boyd Baumgartner]

Michele was nice enough to swing by and confirm in essence what you said as well as provide some nice pics from Bloom & Fawcett's Concise Histology. (thanks again Michele!).

I realize now I had the concept down, and it was more of a matter of contradictory terminology as I was accessing multiple websites. However, I appreciate the 'negative ridge' explanation, I like it better.

I wouldn't mind any further material you may have though.

I can be reached at boyd.baumgartner@metrokc.gov

thanks,

Boyd

[D. Tivin]

Kasey,
I would be very interested in recieving the article as well.
I also think posting the diagrams would be great.

Thanks,
Dave Tivin