The area between the thigh and groin is often referred to by various terms. Understanding its precise anatomical terminology helps in discussing its structures and functions accurately. This article clarifies the correct anatomical names for this area and details the components found within it.
The Primary Anatomical Term
The anatomical area encompassing the groin is known as the “inguinal region.” This region is located in the lower portion of the anterior abdominal wall, superior to the thigh. Within the inguinal region, a specific triangular depression in the upper thigh is termed the “femoral triangle,” also known as Scarpa’s triangle.
The femoral triangle is a subfascial space. This area is accessible and serves as a passageway for several neurovascular structures. Its name, “femoral triangle,” directly relates to the femur and its triangular shape.
Defining the Region’s Location
The femoral triangle has distinct borders that define its triangular shape in the upper thigh. The superior border, forming the base of the triangle, is the inguinal ligament. This strong band of connective tissue extends from the anterior superior iliac spine to the pubic tubercle.
The lateral border of the femoral triangle is formed by the medial edge of the sartorius muscle. The medial border of the femoral triangle is created by the medial edge of the adductor longus muscle, which is located on the inner thigh. The meeting point of the sartorius and adductor longus muscles forms the apex of the triangle, which points downwards.
Key Structures and Their Roles
The femoral triangle serves as a conduit for several structures that pass between the abdomen and the lower limb. These contents include the femoral nerve, femoral artery, femoral vein, and lymph nodes. These structures are arranged from lateral to medial within the triangle, often remembered by the mnemonic NAVEL (Nerve, Artery, Vein, Empty space/Lymphatics).
The femoral artery is a blood vessel that carries oxygen-rich blood from the heart to the entire lower limb. It is a continuation of the external iliac artery, changing its name as it passes beneath the inguinal ligament. This artery is used for checking pulse and for various medical procedures due to its superficial location within the triangle.
Accompanying the femoral artery is the femoral vein, a blood vessel responsible for returning deoxygenated blood from the lower limb back to the heart. It lies medial to the femoral artery within the triangle. The femoral nerve, a nerve of the lumbar plexus, is located lateral to the femoral artery and vein. It provides motor control for hip flexion and knee extension, and sensory innervation to the skin of the anterior and medial thigh.
The femoral triangle also contains lymph nodes, specifically the superficial and deep inguinal lymph nodes. These small, bean-shaped glands are part of the immune system. They filter lymph fluid, removing bacteria, viruses, and other foreign substances from the lower limbs, genitals, and lower abdominal wall. Swelling of these lymph nodes can indicate an infection or other medical conditions in the areas they drain.