Bones The
femur is the only bone in the thigh and serves as an attachment site for all thigh muscles. The
head of the femur articulates with the
acetabulum in the
pelvic bone forming the
hip joint, while the
distal part of the femur articulates with the
tibia and
patella forming the
knee. By most measures, the femur is the strongest and longest bone in the body. The femur is categorised as a
long bone and comprises a
diaphysis,
the shaft (or body) and two
epiphyses, the
lower extremity and the
upper extremity of femur, that articulate with adjacent bones in the hip and knee.
Muscular compartments In cross-section, the thigh is divided up into three separate compartments, divided by
fascia, each containing muscles. These compartments use the femur as an axis and are separated by tough
connective tissue membranes (or
septa). Each of these compartments has its own
blood and
nerve supply, and contains a different group of
muscles. •
Medial fascial compartment of thigh, adductor •
Posterior fascial compartment of thigh, flexion,
hamstring •
Anterior fascial compartment of thigh, extension Anterior compartment muscles of the thigh include
sartorius, and the four muscles that comprise the
quadriceps muscles –
rectus femoris,
vastus medialis,
vastus intermedius and
vastus lateralis. Posterior compartment muscles of the thigh are the
hamstring muscles, which include
semimembranosus,
semitendinosus, and
biceps femoris. Medial compartment muscles are
pectineus,
adductor magnus,
adductor longus and
adductor brevis, and also
gracilis. Because the major muscles of the thigh are the largest muscles of the body, resistance exercises (strength training) of them stimulate blood flow more than any other localized activity.
Blood supply The arterial supply is by the
femoral artery and the
obturator artery. The lymphatic drainage closely follows the arterial supply and drains to the lumbar lymphatic trunks on the corresponding side, which in turn drains to the
cisterna chyli. The deep venous system of the thigh consists of the
femoral vein,
common femoral vein,
deep femoral vein, the proximal part of the
popliteal vein, and various smaller vessels; thighs are the site of proximal
deep vein thrombosis. The
perforating veins connect the deep and the superficial system, which consists of the
small and
great saphenous veins (the site of
varicose veins). ==Clinical significance==