The leg is the entire lower limb of the human body, including the foot, thigh or sometimes even the hip or buttock region. The major bones of the leg are the femur, tibia, and adjacent fibula. The thigh is between the hip and knee, while the calf (rear) and shin (front) are between the knee and foot.
The sciatic nerve, also called the ischiadic nerve, is a large nerve in humans and other vertebrate animals which is the largest branch of the sacral plexus and runs alongside the hip joint and down the lower limb. It is the longest and widest single nerve in the human body, going from the top of the leg to the foot on the posterior aspect. The sciatic nerve has no cutaneous branches for the thigh. This nerve provides the connection to the nervous system for the skin of the lateral leg and the whole foot, the muscles of the back of the thigh, and those of the leg and foot. It is derived from spinal nerves L4 to S3. It contains fibers from both the anterior and posterior divisions of the lumbosacral plexus.
In human anatomy, the fibularis longus is a superficial muscle in the lateral compartment of the leg. It acts to tilt the sole of the foot away from the midline of the body (eversion) and to extend the foot downward away from the body at the ankle.
The tibia, also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates ; it connects the knee with the ankle. The tibia is found on the medial side of the leg next to the fibula and closer to the median plane. The tibia is connected to the fibula by the interosseous membrane of leg, forming a type of fibrous joint called a syndesmosis with very little movement. The tibia is named for the flute tibia. It is the second largest bone in the human body, after the femur. The leg bones are the strongest long bones as they support the rest of the body.
The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity is small, placed toward the back of the head of the tibia, below the knee joint and excluded from the formation of this joint. Its lower extremity inclines a little forward, so as to be on a plane anterior to that of the upper end; it projects below the tibia and forms the lateral part of the ankle joint.
The popliteal artery is a deeply placed continuation of the femoral artery opening in the distal portion of the adductor magnus muscle. It courses through the popliteal fossa and ends at the lower border of the popliteus muscle, where it branches into the anterior and posterior tibial arteries.
The gastrocnemius muscle is a superficial two-headed muscle that is in the back part of the lower leg of humans. It is located superficial to the soleus in the posterior (back) compartment of the leg. It runs from its two heads just above the knee to the heel, extending across a total of three joints.
The posterior tibial artery of the lower limb is an artery that carries blood to the posterior compartment of the leg and plantar surface of the foot. It branches from the popliteal artery via the tibial-fibular trunk.
The anterior tibial artery is an artery of the leg. It carries blood to the anterior compartment of the leg and dorsal surface of the foot, from the popliteal artery.
The biceps femoris is a muscle of the thigh located to the posterior, or back. As its name implies, it consists of two heads; the long head is considered part of the hamstring muscle group, while the short head is sometimes excluded from this characterization, as it only causes knee flexion and is activated by a separate nerve.
The adductor magnus is a large triangular muscle, situated on the medial side of the thigh.
In human anatomy, the fibularis brevis is a muscle that lies underneath the fibularis longus within the lateral compartment of the leg. It acts to tilt the sole of the foot away from the midline of the body (eversion) and to extend the foot downward away from the body at the ankle.
The common fibular nerve is a nerve in the lower leg that provides sensation over the posterolateral part of the leg and the knee joint. It divides at the knee into two terminal branches: the superficial fibular nerve and deep fibular nerve, which innervate the muscles of the lateral and anterior compartments of the leg respectively. When the common fibular nerve is damaged or compressed, foot drop can ensue.
The deep fibular nerve begins at the bifurcation of the common fibular nerve between the fibula and upper part of the fibularis longus, passes infero-medially, deep to the extensor digitorum longus, to the anterior surface of the interosseous membrane, and comes into relation with the anterior tibial artery above the middle of the leg; it then descends with the artery to the front of the ankle-joint, where it divides into a lateral and a medial terminal branch.
The popliteal fossa is a shallow depression located at the back of the knee joint. The bones of the popliteal fossa are the femur and the tibia. Like other flexion surfaces of large joints, it is an area where blood vessels and nerves pass relatively superficially, and with an increased number of lymph nodes.
The anterior compartment of the leg is a fascial compartment of the lower leg. It contains muscles that produce dorsiflexion and participate in inversion and eversion of the foot, as well as vascular and nervous elements, including the anterior tibial artery and veins and the deep fibular nerve.
The lateral compartment of the leg is a fascial compartment of the lower leg. It contains muscles which make eversion and plantarflexion of the foot.
The posterior compartment of the thigh is one of the fascial compartments that contains the knee flexors and hip extensors known as the hamstring muscles, as well as vascular and nervous elements, particularly the sciatic nerve.
A neurovascular bundle is a structure that binds nerves and veins with connective tissue so that they travel in tandem through the body.
The following outline is provided as an overview of and topical guide to human anatomy:
