AN44.1-7 | Anterior abdominal wall — Summary & Reflection

REFLECT

KEY TAKEAWAYS

Module Summary — Anterior Abdominal Wall

• Regions/Quadrants: 4 quadrants for clinical use; 9 regions for academic use. Transpyloric plane (L1) is the most clinically important plane.
• Muscles: 3 flat muscles laterally (EO, IO, TA in crossing layers) + rectus + pyramidalis centrally. Transversus is the main Valsalva muscle.
• Fascia: Camper's (fatty) → Scarpa's (membranous) → aponeuroses → transversalis fascia. Scarpa's fascia confines urinary extravasation.
• Rectus sheath: Formed differently above vs below the arcuate line. Above: EO + anterior IO anteriorly; posterior IO + TA posteriorly. Below: all three aponeuroses anteriorly; transversalis fascia only posteriorly.
• Inguinal canal: 4 cm, oblique. Deep ring in transversalis fascia; superficial ring in EO aponeurosis. Indirect hernia → lateral to IEA, through full canal. Direct hernia → medial to IEA, through Hesselbach's triangle.
• Incisions: Midline (fastest, more hernia), Kocher's (cholecystectomy), gridiron (appendix, self-sealing), Pfannenstiel (caesarean, cosmetic), laparoscopic ports (avoid IEA).