AN44.1-7 | Anterior abdominal wall — Glossary

Largest and most superficial flat abdominal muscle with fibres directed downward and medially; its aponeurosis forms the inguinal ligament and superficial inguinal ring

Middle flat abdominal muscle with fibres directed upward and medially; its aponeurosis splits to form the anterior and posterior walls of the rectus sheath above the arcuate line

Deepest flat abdominal muscle with horizontal fibres; its aponeurosis contributes to the posterior rectus sheath above the arcuate line and the conjoint tendon

Vertical paired muscle from pubic crest to xiphoid and costal cartilages 5-7; divided by tendinous intersections; enclosed in the rectus sheath

Midline fibrous raphe from xiphoid to pubic symphysis formed by fusion of all three flat muscle aponeuroses; avascular, used for midline laparotomy

Free lower border of the posterior rectus sheath; below it, all three aponeuroses pass anterior to the rectus, and the inferior epigastric artery enters the sheath

Membranous deep layer of the superficial fascia of the abdomen; fused with fascia lata below the inguinal ligament; confines urinary extravasation

Oblique passage (~4 cm) through the anterior abdominal wall from the deep inguinal ring to the superficial ring; transmits the spermatic cord in males and round ligament in females

Rolled-under free lower edge of the external oblique aponeurosis from the ASIS to the pubic tubercle; forms the floor of the inguinal canal

Oval opening in the transversalis fascia lateral to the inferior epigastric vessels; the entrance to the inguinal canal

Triangular opening in the external oblique aponeurosis above and lateral to the pubic tubercle; the exit of the inguinal canal

Triangular area bounded by the rectus laterally, inferior epigastric vessels laterally, and inguinal ligament inferiorly; site of direct inguinal hernia

Branch of the external iliac artery; the key landmark distinguishing direct (medial) from indirect (lateral) inguinal hernias

Fused aponeuroses of the internal oblique and transversus abdominis inserting into the pubic crest; reinforces the posterior wall of the inguinal canal medially

Structure traversing the inguinal canal in males; contains the vas deferens, testicular artery, pampiniform plexus, and genital branch of genitofemoral nerve

Hernia entering the deep ring lateral to the inferior epigastric vessels; follows the spermatic cord; may descend into the scrotum; often congenital

Hernia pushing through Hesselbach's triangle medial to the inferior epigastric vessels; acquired weakness of transversalis fascia; rarely enters the scrotum

Outpouching of peritoneum accompanying testicular descent; patent processus vaginalis predisposes to indirect inguinal hernia and communicating hydrocele

Deep fascia lining the inner surface of the transversus abdominis; forms the posterior wall of the inguinal canal and the deep inguinal ring

Fatty superficial layer of the superficial fascia of the anterior abdominal wall; continuous with subcutaneous fat elsewhere

Point one-third of the way from the ASIS to the umbilicus; surface marking for the base of the appendix; tenderness here suggests appendicitis