4 Abdominopelvic Regions and Quadrants

To promote clear communication about the location of a patient’s abdominal pain or a suspicious mass, healthcare providers typically divide up the cavity into either nine regions or four quadrants (Figure 1.12).

The more detailed regional approach subdivides the cavity with one horizontal line immediately inferior to the ribs and one immediately superior to the pelvis, and two vertical lines drawn as if dropped from the midpoint of each clavicle (collarbone). There are nine resulting regions. The simpler quadrants approach, which is more commonly used in medicine, subdivides the cavity with one horizontal and one vertical line that intersect at the patient’s umbilicus (navel).