inguinal

Inguinal refers to the groin region, the area of the lower anterior abdominal wall where the abdomen meets the thigh. The inguinal region is clinically important because it contains the inguinal canal and is a common site for hernias.

Anatomy

The inguinal canal is a short, oblique passage about 4 cm long in adults. It runs parallel to and just superior to the inguinal ligament, which forms its floor. The anterior wall consists largely of the aponeurosis of the external oblique and contributions from the internal oblique. The posterior wall is formed by the transversalis fascia, with reinforcement from the conjoint tendon medially. The roof is created by the arching fibers of the internal oblique and transversus abdominis.

Openings

The deep inguinal ring is a defect in the transversalis fascia, located [lateral to the inferior epigastric vessels]. The superficial inguinal ring is an opening in the external oblique aponeurosis, lying just above the medial half of the inguinal ligament.

Contents

In males, the inguinal canal transmits the spermatic cord, which contains the vas deferens, testicular vessels, and accompanying nerves and vessels. In females, the canal contains the round ligament of the uterus. The ilioinguinal nerve and, in some cases, branches of the genitofemoral nerve also pass through or near the canal.

Clinical relevance

Hernias are common in the inguinal region. Indirect inguinal hernias pass through the deep ring into the canal and are more common in men; direct hernias protrude through a weakness in the posterior wall, via Hesselbach’s triangle. Lymphatic drainage involves superficial and deep inguinal nodes, related to the skin of the lower abdomen, scrotum or labia majora, and portions of the lower limb.