Friction Ridge
Definition
Raised epidermal ridge on the palmar surface of fingers, palms and soles, formed during foetal life from the underlying dermal papillae. The pattern is what gets recorded as a fingerprint.
- Location
- Fingers, palms, and soles
- Formed by
- Underlying dermal papillae, during foetal development
- Recorded as
- Fingerprint
- Field
- Fingerprint identification
Common questions
How does the friction ridge relate to the level 1, 2, and 3 detail examiners use for identification?+
The overall friction ridge flow forms level 1 detail such as loops, whorls, and arches; the ridge path itself produces level 2 minutiae like bifurcations and ridge endings; and the ridge edge shape and pore positions along it form level 3 detail, so the ridge is the physical structure all three levels are read from.
Why do friction ridges provide reliable long-term identification?+
Because their pattern is fixed by dermal papillae architecture before birth and the ridge structure regenerates in the same configuration after superficial injury, the overall pattern remains stable across a person's lifetime barring deep scarring that damages the dermis itself.
Related terms
- ACE-V
- Analysis, Comparison, Evaluation, Verification: the four-stage method for latent print examination used by accredited forensic fingerprint laboratories. Analysis examines the latent in...
- Adermatoglyphia
- Rare genetic disorder, sometimes called immigration delay disease, in which a person is born without friction ridges. The standard counter-example to the...
- Core
- The approximate centre of a fingerprint pattern. In a loop, it is identified as the innermost recurving ridge's peak or the tip...
- Delta
- Triangular ridge formation at the point where parallel ridge flows diverge. Arches have 0 deltas, loops have 1, whorls have 2 or...
- Dermal Papillae
- Peg-like projections of the dermis into the epidermis. Their geometry sets the ridge pattern in stone before birth. Damage limited to the...
- Henry Classification
- Numeric filing system built at the Calcutta Fingerprint Bureau in 1897. Assigns a numerator and denominator from whorls on even and odd...
- Minutiae (Galton Points)
- Local ridge features used for individual identification. The classical set is ridge ending, bifurcation, dot, island or lake, bridge, hook or spur,...