Anatomy of the Thigh

The Thigh

• The thigh comprises skin, superficial fascia, deep fascia, and muscles.

Superficial Fascia

• The superficial fascia of the anterior abdominal wall extends down to the thigh.
• It's composed of 2 layers: superficial fatty layer and deep membranous layer.
• The fatty layer continues down the lower limb without interruption.
• The membranous layer attaches to the deep fascia (fascia lata) below the inguinal ligament.
• The superficial fascia contains superficial inguinal vessels, lymph nodes, and the great saphenous vein.

Deep Fascia of the Thigh (Fascia Lata)

• Fascia lata is a tough fibrous sheet enveloping the thigh.
• Superiorly, it's attached to the inguinal ligament, iliac crest, sacrum, coccyx, sacrotuberous ligament, and pubis, pubic arch, ischial tuberosity.
• Inferiorly, it's attached to the front and sides of the knee (femur, tibia, patella, and fibula).
• It thickens laterally to form the iliotibial tract, extending from the tubercle of the iliac crest to the lateral condyle of the tibia.
• Includes intermuscular septa dividing the thigh into 3 compartments.

Intermuscular Septa

• Three intermuscular septa divide the thigh into 3 compartments: anterior, medial, and posterior.
• The lateral septum extends from the lateral lip of the linea aspera to the iliotibial tract.
• The medial septum extends from the medial lip of the linea aspera to the deep fascia on the medial side
• The posterior septum extends from the medial lip of the linea aspera to the deep fascia on the posterior side, being poorly defined.

Compartments of the Thigh

• Anterior compartment:
  • Muscles: sartorius, iliacus, psoas major, quadriceps femoris.
  • Blood supply: Femoral artery.
  • Nerve supply: Femoral nerve.
• Medial compartment:
  • Muscles: gracilis, pectineus, adductor longus, adductor brevis, adductor magnus, obturator externus.
  • Blood supply: Obturator and profunda femoris arteries.
  • Nerve supply: Obturator nerve.
• Posterior compartment:
  • Muscles: biceps femoris, semitendinosus, semimembranosus (hamstrings).
  • Blood supply: branches from profunda femoris artery.
  • Nerve supply: sciatic nerve.

Muscles of the Thigh

• Various muscles are detailed (Sartorius, Iliacus, Psoas, Pectineus, Rectus Femoris etc). Each muscle has its origin, insertion, nerve supply, actions etc.

Quadriceps Femoris Muscle

• The quadriceps femoris is a large muscle with four parts: rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius.
• Its origin and function are described.

Lateral and Medial Patellar Ligaments

• These ligaments extend from vastus lateralis and medialis into the knee joint capsule.
• Nerve supply: Femoral nerve.

Articularis Genu Muscle

• A small muscle that originates from the femur and inserts into the synovial membrane associated with the knee joint.
• Its action involves pulling the synovial membrane during extension.