Comparative and Functional Morphology of the Primate Hand Integument

The integument of primate hands (i.e., skin and nails) are specialized to interact with the outside world. The integument of the palm is arranged into a series of fleshy volar pads, while hardened nails grow from the skin overlying the tips of the digits. The volar skin provides friction which enhances climbing ability and the prehension of objects, but also contains important mechanoreceptors for tactile acuity. Primate nails are highly diverse in structure and likely play a number of different roles related to locomotion, grasping, and tactile sensitivity. This chapter provides a comprehensive review of the integument of primate hands. First, the structure of volar skin and nails is discussed. This is followed by a review of the anatomical diversity among nonhuman primates and a discussion of the functional significance of different specializations. The chapter ends with avenues for future study.