A feline fancier is most likely to be familiar with that sandpaper feeling of the cat’s tongue. The cat’s tongue is a marvelous and highly specialized organ that features backward-facing barb like structures called papillae. While not normally noticed at normal viewing distances, the papillae are easily revealed close up in a macro photographic view.
The commonly accepted purposes of the papillae are to aid in grooming and to tear flesh from the bone of prey. The papillae are composed of keratin which is found in human finger nails. Cat grooming is suspected to be a survival adaptation. As a small predator, it is important that all traces of their last meal be removed to make tracking by larger prey more difficult. Cats have fewer taste buds relative to other mammals. A trade off in the topology of a tongue blessed with the sandpaper quality produced by the papillae leaving less room for taste buds.
Photograph taken with the explicit permission of our average feline companion who tolerates our presence in its domicile. Nikon 610 with Nikor 105mm f2.8 macro lens. Email me for details on this photo including camera settings. Hint: No flash, high ISO. Cats do not tolerate the flash very well at all.