Anatomy of the Anterior Abdominal Wall

The anterior abdominal wall is composed of six layers: skin, superficial fascia, muscles, deep fascia, extraperitoneal fat, and parietal peritoneum.

The superficial fascia of the anterior abdominal wall has two layers: Camper's fascia (fatty) and Scarpa's fascia (deep membranous).

The external oblique muscle is one of the major muscles of the anterior abdominal wall, its fibers run downwards and medially.

The internal oblique muscle lies beneath the external oblique, its fibers run upwards and medially.

The transversus abdominis muscle is the deepest of the three anterolateral abdominal muscles, and its fibers run horizontally.

The rectus abdominis is a long, vertical muscle running down the midline of the abdomen, commonly known as the 'six-pack' muscle.

The pyramidalis muscle is a small, triangular muscle located in the lower part of the abdomen, anterior to the rectus abdominis.

The psoas major muscle is a large, powerful muscle located in the posterior abdominal wall, responsible for hip flexion.

The iliacus muscle is located in the iliac fossa, working alongside the psoas major to flex the hip.

The quadratus lumborum muscle is a deep muscle of the posterior abdominal wall, responsible for lateral flexion of the lumbar spine.

The inguinal ligament is a strong, fibrous band formed by the lower border of the external oblique aponeurosis, connecting the anterior superior iliac spine to the pubic tubercle.

The inguinal canal is an oblique passage in the lower part of the anterior abdominal wall, through which the spermatic cord in males or the round ligament in females passes.

An indirect inguinal hernia occurs when a portion of the intestine protrudes through the deep inguinal ring, then through the superficial inguinal ring.

A direct inguinal hernia occurs when a portion of the intestine protrudes directly through the inguinal triangle, medial to the inferior epigastric artery.

The abdomen is divided into nine regions by two vertical midclavicular lines and two horizontal lines (subcostal and transtubercular).

The peritoneum is a serous membrane that lines the abdominal cavity and covers the abdominal organs.

The parietal peritoneum lines the interior of the anterior and posterior abdominal walls and the lower surface of the diaphragm.

The visceral peritoneum surrounds the abdominal organs, forming their outer covering.

The foregut is the first part of the digestive system, including the abdominal esophagus, stomach, duodenum, liver, spleen, and pancreas.

The midgut is the middle part of the digestive system, including the lower duodenum, jejunum, ileum, and most of the large intestine.

The hindgut is the final part of the digestive system, including the remaining portion of the large intestine and anal canal.

The celiac trunk is the main blood supply for the foregut, branching into the left gastric, splenic, and common hepatic arteries.

The superior mesenteric artery is the main blood supply for the midgut, supplying the small intestine and part of the large intestine.

The inferior mesenteric artery is the main blood supply for the hindgut, supplying the rest of the large intestine.