Corpus: Thigh
1. Definition
The term thigh refers to the proximal portion of the lower limb. It connects to the lower leg through the knee joint and to the trunk via the hip joint.
2. Topography
The thigh is bordered proximally by the inguinal groove at the front and the gluteal crease at the back. Distally, it ends about 4–5 cm above the patella. Its muscular structure primarily determines its shape.
The front part of the thigh is referred to as the anterior femoral region, which includes the femoral triangle. The back part is called the posterior femoral region.
4. Musculature
The femur serves as the point of orign or attachment for many muscles, including muscles of the hip and lower leg. However, the bulk of the thigh is composed of its own muscles, which are grouped into three categories:
4.1. Thigh leg extensors
4.2. Femoral flexors
4.3. Femoral adductor muscles
- Pectineus muscle
- Adductor longus muscle
- Adductor brevis muscle
- Adductor magnus muscle
- Gracilis muscle
Some authors consider the adductor muscles as part of the hip musculature.
5. Pathways
5.1. Arteries
The primary artery of the thigh is the femoral artery, which is a continuation of the external iliac artery. At the knee joint, it transitions into the popliteal artery. Additionally, blood supply to regions near the gluteal area comes from branches of the internal iliac artery.
5.2. Veins
Venous blood from the lower limb is drained through two systems:
- Superficial veins: the great saphenous vein and the small saphenous vein, which lie above the fascia.
- Deep veins: the popliteal vein and the deep femoral vein, located beneath the fascia.
Both systems ultimately drain into the femoral vein, which runs alongside the femoral artery.
5.3. Nerves
The major nerves of the thigh originate from the lumbosacral plexus and include:
Other significant nerves in the thigh include: