Medial Thigh Anatomy Quiz

Medial Thigh Anatomy

• The medial thigh comprises muscles, nerves, and vascular structures.
• The muscles of the medial thigh include Gracilis, Pectineus, Adductor longus, Adductor brevis, and Adductor magnus.
• Obturator externus is also discussed in the context of the surrounding gluteal region.

Muscle Details

• Gracilis: Originates from the pubic body, inserts on the medial tibia, and functions in hip adduction, knee flexion, and medial rotation. Innervated by the Obturator nerve (L2-L3).
• Pectineus: Originates from the pectineal surface of the pubis, inserts between the lesser trochanter and the linea aspera. It adducts the thigh at the hip. Innervated by the femoral nerve (L2-L3) and possibly the obturator nerve.
• Adductor longus: Originates from the pubic crest, inserts on the linea aspera (mid-third). Functions in hip adduction. Innervated by the obturator nerve (L2-L4).
• Adductor brevis: Originates from the body and inferior ramus of pubis, inserts on the linea aspera. It adducts the thigh. Innervated by the obturator nerve (L2-L4).
• Adductor magnus: Originates from the ischiopubic ramus and ischial tuberosity. It inserts on the adductor portion, posterior part of the femur from gluteal tuberosity to the medial supra-condylar ridge, and the adductor tubercle. It functions in hip adduction and thigh extension. Innervated by the obturator (L3-L4) and sciatic nerve (L4-L5).

Adductor Canal and Hiatus

• The adductor canal is a passageway for femoral artery, vein, saphenous nerve, and lymph vessels.
• It begins at the inferior apex of the femoral triangle and ends at the adductor hiatus.
• The canal's borders are the sartorius, adductor longus and magnus, and vastus medialis and intermedius.
• Importantly, the great saphenous vein is NOT in the canal.

Nerves

• The major nerve to the medial thigh muscles is the obturator nerve (L2-L4).
• This nerve has both anterior and posterior divisions which supply the muscles.
• Additional nerves include branches from the femoral nerve (medial femoral cutaneous) and possibly a bit of the ilioinguinal nerve providing sensory innervation for the skin.
• Nerve lesions can lead to pain, paraesthesia, loss of sensation, and loss of hip adduction.

Vascular Structures

• Arterial Supply: Profunda femoris and medial/lateral circumflex, and four perforating arteries contribute.
• Profunda femoris artery: Major branch arising on the lateral thigh, 3-5 cm below the inguinal ligament. It curves over adductor brevis and behind the femoral artery and vein to reach the medial thigh. Perforating branches pass between the femur and the tendon of adductor magnus.
• Obturator artery: Arises from the internal iliac artery, travels through the obturator canal, dividing into medial and lateral branches for muscles and hip joint supply.
• Venous Drainage: The obturator vein (ObV) drains into the internal iliac vein. The profunda femoris vein (PFV) drains into the femoral vein.

Summary of Study Points

• Students should be able to identify and describe the actions of the medial thigh muscles.
• Students should know which muscles and nerves are supplied by which nerves.
• The vascular structures important in the medial thigh should be recognised and understood.
• Note the clinical correlations with nerve lesion.

Further Study

• Review of vascular structures and nerves of the medial thigh.
• Preparation for next week's lecture on the gluteal region.