Palmar and plantar pads and flexion creases of the rat (Rattus norvegicus)

Abstract

The recent detection of dermal ridge configurations on the volar pads of the rat (Rattus norvegicus) has created opportunities for experimental studies of dermatoglyphics. In the present work, the palmar and plantar surfaces of the rat were studied to establish the feasibility of comparative rat and human dermatoglyphic investigations. The studied features included the volar pads and flexion creases. The number and location of the palmar and plantar pads in the rat were found to be similar to those of humans. The exception was a previously unrecognized small pad on the palms and soles of the rat, located on the radial and tibial side, respectively, of the proximal component of the first interdigital pad. This pad has no parallel in human embryos. Rats were found to have flexion creases in the non-pad areas between the neighboring pads, similar in location and appearance to those of humans. Unlike humans, however, rats also have boundary creases, separating the pad and non-pad areas. The marked similarities in the morphology of the volar areas between rats and humans make the rat ideally suitable for experimental studies of dermatoglyphics and flexion creases. Results of such studies should be applicable to human developmental dermatoglyphics, including those pertaining to medical disorders.

Normal Location Of Thumb/Big Toe may be Related to Programmed Cell Death in the Preaxial Area of Embryonic Limb

“…The morphological terms for describing the major pads and flexion creases are essentially the same as those used for rats (Rattus norvegicus) (Brown and Yalden, 1973;Okajima and Asai, 1985;Okajima, 1991;Kimura et al, 1994), newborn rats , and field mice (Microtus) (Whipple, 1904). The palmar and plantar surfaces of mice and rats share morphological features, including pads and flexion creases.…”

Comparative investigations of human and rat dermatoglyphics: palmar, plantar and digital pads and flexion creases

“…On the sole, the pads are very similar to those of the palm. The only difference is an extra small pad (Esp) in the distal portion of the proximal component of the first interdigital pad on the palm which has no equivalent on the sole (Kimura et al. , 1994).…”

“…, 1994). The palmar and plantar surfaces look similar, except for the retarded thumb, the extra small pad, the shorter or more compressed thenar/first interdigital area and the larger size of the proximal component of the hypothenar pad found on the palm (Kimura et al. , 1994).…”

“…Creases : bc, boundary crease; etc, extra transverse crease; ftc, fibular transverse crease; lc, longitudinal crease; rtc, radial transverse crease; ttc, tibial transverse crease; utc, ulnar transverse crease; wc, wrist crease. Bars = 3 mm (from Kimura et al. , 1994, with permission).…”

“…The boundary creases surrounding each palmar pad start emerging as faint lines bordering the pads. These creases, which have no equivalent in humans, were named boundary creases by Kimura et al . (1994), because they separate the pad areas with high prominence from the non‐pad areas.…”