Abdominalwall

The abdominal wall refers to the boundaries of the abdominal cavity formed by skin, fascia, muscles, and underlying structures that extend from the thorax to the pelvis. It serves to protect the abdominal viscera, maintain posture, and generate intra-abdominal pressure necessary for respiration, defecation, micturition, and childbirth. It also assists with trunk movements and provides a foundation for organ support.

The muscular component consists of the external oblique, internal oblique, transversus abdominis, and rectus abdominis. Their aponeuroses contribute to the anterior rectus sheath and to the linea alba, a fibrous midline seam that joins the two rectus muscles. The rectus abdominis lies within the anterior wall and is associated with the semilunar lines laterally. Above the arcuate line, there is a posterior rectus sheath; below it, the posterior sheath is absent, and the rectus rests on the transversalis fascia.

The abdominal wall is reinforced by fascial layers and planar connections, including Campers fascia (superficial), Scarpa’s fascia (deep), the transversalis fascia, and the peritoneum. The inguinal canal courses through the lower anterior wall, housing the spermatic cord in males or the round ligament in females, and features the superficial and deep inguinal rings.

Innervation is provided primarily by the thoracoabdominal nerves (T7–T11), the subcostal nerve (T12), and the iliohypogastric and ilioinguinal nerves (L1). Blood supply comes from the superior and inferior epigastric arteries, with contributions from intercostal and deep circumflex iliac arteries.

Clinically, the abdominal wall is involved in conditions such as hernias (inguinal, umbilical, incisional), diastasis of the rectus abdominis, and abdominal wall trauma or weakness affecting function.