Rugae is a term used in anatomy that refers to a series of ridges produced by folding of the wall of an organ. Most commonly the term is applied to the internal surface of the stomach (gastric rugae). The function of the rugae is to allow the stomach, or other tissue, to expand when needed. When the stomach is not full, the rugae are folds in the tissue. However, as the stomach fills it expands by unfolding the rugae. When the stomach empties again, it refolds and the rugae increase to their former size. Other locations that rugae appear in humans:

  • Wrinkles of the scrotum
  • Hard palate immediately behind the upper anterior teeth
  • Inside the Urinary bladder
  • Vagina
  • Gallbladder
  • Inside the stomach

Other articles related to "rugae":

Longisquama - Description - Integumentary Structures
... The middle ridged lobe is made up of raised "rugae" and deep "interstices," which Sharov compared to rosary beads ... In some specimens, the rugae of either lobe in the distal section line up with each other, while in other specimens they do not ... Some specimens have straight rugae projecting perpendicular to the axis, while others have rugae that curve in an S-shape ...
Myrmica Laevinodis
... However, the unraised rugae on the posterodorsal portion of the mesonotum are usually characteristic, though some M ... rubra has fewer strong rugae, and is more smooth on the lower half of the mesonotal pleura than M ... kotokui its propodeal spines are shorter, and the rugae on the anterior basal portion of the 1st gastral tergite are relatively weak and fewer in number ...
Ballard Maturational Assessment - The Physical Criteria
... ear stiff Genitals (Male) Scrotum flat, smooth Scrotum empty, faint rugae Testes in upper canal, rare rugae Testes descending, few rugae Testes down, good rugae Testes pendulous, deep rugae Genitals (Female ...