What is the posterior abdominal wall and what does it do?

The posterior abdominal wall is a strong, stable structure that extends from the 12th rib above to the pelvic brim below. It supports retroperitoneal organs, major vessels, and nerves, unlike the softer anterior abdominal wall.

What bones make up the bony framework of the posterior abdominal wall?

The bony framework includes: in the median plane, lumbar vertebral bodies, intervertebral discs, and transverse processes (L1–L5); laterally above the iliac crest, inner surfaces of the 12th ribs; and laterally below the iliac crest, iliac fossae of the hip bones.

What muscles are found in the posterior abdominal wall?

The musculature is arranged from medial to lateral: above the iliac crest, psoas major, quadratus lumborum, and transversus abdominis; below the iliac crest, psoas major and iliacus.

How are the muscles of the posterior abdominal wall covered by fascia?

The psoas major and iliacus are covered by the fascia iliaca. The quadratus lumborum is enclosed between the anterior and posterior layers of the thoracolumbar fascia, which helps compartmentalize and stabilize these muscles.

What key structures are associated with the posterior abdominal wall?

Key structures include great vessels like the abdominal aorta and inferior vena cava (IVC), azygos and hemiazygos veins, lymph nodes and lymphatic vessels, and nerves of the lumbar plexus.

What forms the superior boundary of the posterior abdominal wall?

The diaphragm completes the upper part of the posterior abdominal wall, serving as its superior boundary.

Posterior Abdominal Wall – Muscles, Fascia & Nerves