A ridge or fold, such as the rugae of the stomach, which are large folds in the mucous membrane of that organ. [ http://medical-dictionary.thefreedictionary.com/Rugal+folds http://en.wikipedia.org/wiki/Rugae ]
Synonyms: ruga
Term information
As currently defined this encompasses only mucuous membranes, and not for example rugal folds of skin such as the scrotal rugae