abdominal quadrant, any of four topographic areas of the abdomen divided by two imaginary lines, one vertical and one horizontal, intersecting at the umbilicus. The divisions are the left upper quadrant (LUQ), the left lower quadrant (LLQ), the right upper quadrant (RUQ), and the right lower quadrant (RLQ). Quadrants are most commonly utilized in clinical examination and practice. Compare abdominal regions.
