Groin

Gross anatomy

Where the lower part of the anterior abdominal wall meets the thigh, a crease is formed known as the inguinal groove or crease. The junction is the area of the medial compartment of the thigh that contains the attachments of the adductor muscles of the hip, also known as the groin muscles.

The adductor muscles that make up the groin consist of the adductor brevis, adductor longus, adductor magnus, gracilis, and pectineus. These groin muscles adduct the thigh (bring the thigh and knee closer to the midline).

The groin is innervated by branches of the lumbar plexus. The pectineus muscle is innervated by the femoral nerve, and the hamstring portion of adductor magnus is innervated by the tibial nerve.

In the groin, underneath the skin, there are three to five deep inguinal lymph nodes that play a role in the immune system. A chain of superficial inguinal lymph nodes drain to the deep nodes.

There are two depressions called fossae in an area called the inguinal triangle—the lateral inguinal fossa and the medial inguinal fossa.

The inguinal ligament runs from the pubic tubercle to the anterior superior iliac spine, and its anatomy is important for hernia operations.