
Rete pegs (aka rete processes or rete ridges or papillae) are epithelial extensions that project into the underlying connective tissue in both skin and mucous membranes.
In the epithelium of the mouth, the attached gingiva exhibit rete pegs, while the sulcular and junctional epithelia do not.
- Itoiz, ME; Carranza, FA: The Gingiva. In Newman, MG; Takei, HH; Carranza, FA; editors: Carranza’s Clinical Periodontology, 9th Edition. Philadelphia: W.B. Saunders Company, 2002. pages 23.
- Page, RC; Schroeder, HE. “Pathogenesis of Inflammatory Periodontal Disease: A Summary of Current Work.” Lab Invest 1976;34(3):235-249
Scar tissue lacks rete pegs and scars tend to shear off more easily than normal tissue as a result.
Ira D. Papel (2011). Facial Plastic and Reconstructive Surgery (Third ed.). USA: Thieme Medical Publishers. p. 7. ISBN 9781588905154.
Also known as papillae, they are downward thickenings of the epidermis between the dermal papillae.
Rete Pegs or Ridges and Fingerprints

A friction ridge is a raised portion of the epidermis on the digits (fingers and toes), the palm of the hand or the sole of the foot, consisting of one or more connected ridge units of friction ridge skin. These are sometimes known as “epidermal ridges” which are caused by the underlying interface between the dermal papillae of the dermis and the interpapillary (rete) pegs of the epidermis. These unique features are formed at around the 15th week of fetal development and remain until after death, when decomposition begins. During the development of the fetus, around the 13th week of a pregnancy, ledge-like formation is formed at the bottom of the epidermis beside the dermis. The cells along these ledges begin to rapidly proliferate. This rapid proliferation forms primary and secondary ridges. Both the primary and secondary ridges act as a template for the outer layer of the skin to form the friction ridges seen on the surface of the skin. These epidermal ridges serve to amplify vibrations triggered, for example, when fingertips brush across an uneven surface, better transmitting the signals to sensory nerves involved in fine texture perception. These ridges may also assist in gripping rough surfaces and may improve surface contact in wet conditions.
Ashbaugh, David (1991). “Ridgeology” (PDF). Journal of Forensic Identification. 41 (1): 16–64.
Roberta Kwok (January 29, 2009). “Fake finger reveals the secrets of touch”. Nature. doi:10.1038/news.2009.68. Archived from the original on January 31, 2009. Retrieved January 30, 2009.
“Fingerprint grip theory rejected”. BBC. June 12, 2009. Archived from the original on June 16, 2009. Retrieved June 16, 2009.
References
- Ira D. Papel (2011). Facial Plastic and Reconstructive Surgery (Third ed.). USA: Thieme Medical Publishers. p. 7. ISBN 9781588905154.
- Itoiz, ME; Carranza, FA: The Gingiva. In Newman, MG; Takei, HH; Carranza, FA; editors: Carranza’s Clinical Periodontology, 9th Edition. Philadelphia: W.B. Saunders Company, 2002. pages 23.
- Page, RC; Schroeder, HE. “Pathogenesis of Inflammatory Periodontal Disease: A Summary of Current Work.” Lab Invest 1976;34(3):235-249
- Ashbaugh, David (1991). “Ridgeology” (PDF). Journal of Forensic Identification. 41 (1): 16–64.
- Roberta Kwok (January 29, 2009). “Fake finger reveals the secrets of touch”. Nature. doi:10.1038/news.2009.68. Archived from the original on January 31, 2009. Retrieved January 30, 2009.
- “Fingerprint grip theory rejected”. BBC. June 12, 2009. Archived from the original on June 16, 2009. Retrieved June 16, 2009.
From Wikipedia, the free encyclopedia
Twas poison birds that took us here. There have been experiments to test pitohui batrachotoxins on potential predators. They have been shown to irritate the buccal membranes of brown tree snakes and green tree pythons, both of which are avian predators in New Guinea. The unpalatability of the species is also known to local hunters, who otherwise hunt songbirds of the same size.
Dumbacher, John P.; Menon, Gopinathan K.; Daly, John W. (2009). “Skin as a toxin storage organ in the endemic New Guinean genus Pitohui” (PDF). The Auk. 126 (3): 520–530. doi:10.1525/auk.2009.08230. S2CID 40669290.