Definition

Noun: 1. (Anatomy) A fold, wrinkle, or crease: A ruga is a ridge, fold, or crease, especially one found in the lining of an organ in the body. These folds allow the organ to expand and contract.

Examples of Usage

• The inner surface of the stomach contains numerous rugae that expand to accommodate food.
• Under the microscope, the rugae of the palate are clearly visible.
• The presence of prominent rugae is a normal anatomical feature.

Advanced Usage

• The term is almost exclusively used in medical, anatomical, or biological contexts.
• The plural form rugae is more commonly encountered than the singular ruga.

Variants and Related Words

• Rugae (plural noun): The plural form of .
  • The rugae in the urinary bladder allow it to stretch.

Synonyms

• Fold
• Crease
• Ridge
• Plica (a technical synonym also meaning a fold, especially of membrane or skin)

Notes on Meaning

• Primary Meaning: In anatomy, a specifically refers to a permanent or semi-permanent fold in the mucous membrane of a hollow organ (e.g., stomach, vagina, urinary bladder, hard palate).
• Not a General Wrinkle: It is not typically used to describe wrinkles on the skin from aging; more general terms like "wrinkle" or "crease" are used instead.

Noun

1. (anatomy) a fold or wrinkle or crease
   • rugae of the stomach