Liver and Appendix Anatomy: Not Contralateral Structures

Anatomical Relationship

Contralateral means "on the opposite side." The liver and appendix are not contralateral—both reside in the right side of the abdomen.

Locations

• Liver: Right upper quadrant (RUQ), mostly under the rib cage (segments II–VIII). Extends across midline to left upper quadrant.
• Appendix: Right lower quadrant (RLQ), typically at McBurney's point (⅓ distance from ASIS to umbilicus). Retrocecal, pelvic, or pre-ileal positions common.

Clinical Relevance

• RUQ pain → think liver, gallbladder, right kidney, right colon, right lung base.
• RLQ pain → think appendix, cecum, right ovary/tube, right ureter, Crohn's terminal ileitis.
• Referred pain: Liver capsule stretch → right shoulder (phrenic nerve). Appendix inflammation → periumbilical → RLQ migration.

Understanding ipsilateral (same-side) vs. contralateral relationships aids differential diagnosis and surgical planning.