Thigh

In human anatomy, the thigh is the area between the hip (pelvis) and the knee. Anatomically, it is part of the lower limb.Front of thigh muscles from Gray's Anatomy of the human body from 1918.Back thigh muscles of the gluteal and posterior femoral regions from Gray's Anatomy of the human body from 1918.Cross-section through the middle of the thigh.Also showing major blood vessels and nerves.Cross-section through the middle of the thigh.The Obturator externus In human anatomy, the thigh is the area between the hip (pelvis) and the knee. Anatomically, it is part of the lower limb. The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of bone tissue), and forms a ball and socket joint at the hip, and a modified hinge joint at the knee. The femur is the only bone in the thigh and serves for an attachment site for all muscles in the thigh. 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 kneecap forming the knee. By most measures the femur is the strongest bone in the body. The femur is also the longest bone in the body. The femur is categorised as a long bone and comprises a diaphysis, the shaft (or body) and two epiphysis or extremities that articulate with adjacent bones in the hip and knee. 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. 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.