In human anatomy, the thigh is the area between the hip ( pelvis) and the knee. Anatomically, it is part of the

lower limb The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh or sometimes even the hip or gluteal region. However, the definition in human anatomy refers only to the section of the lower limb ex ...

. The single

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

in the thigh is called the

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. 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 wit ...

. This bone is very thick and strong (due to the high proportion of

bone tissue A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, a ...

), and forms a ball and socket joint at the hip, and a modified hinge joint at the knee.

Structure

Bones

The

is the only bone in the thigh and serves as an attachment site for all muscles in the thigh. The head of the femur articulates with the acetabulum in the

pelvic bone The hip bone (os coxae, innominate bone, pelvic bone or coxal bone) is a large flat bone, constricted in the center and expanded above and below. In some vertebrates (including humans before puberty) it is composed of three parts: the ilium, isch ...

forming the

hip joint In vertebrate anatomy, hip (or "coxa"Latin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) in medical terminology) refers to either an anatomical region or a joint. The hip region is ...

, while the distal part of the femur articulates with the

tibia 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 (the other being the fibula, behind and to the outside of the tibia); it connects ...

and

patella The patella, also known as the kneecap, is a flat, rounded triangular bone which articulates with the femur (thigh bone) and covers and protects the anterior articular surface of the knee joint. The patella is found in many tetrapods, such as ...

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 diaphysis is the main or midsection (shaft) of a long bone. It is made up of cortical bone and usually contains bone marrow and adipose tissue (fat). It is a middle tubular part composed of compact bone which surrounds a central marrow cavit ...

, the shaft (or body) and two

epiphysis The epiphysis () is the rounded end of a long bone, at its joint with adjacent bone(s). Between the epiphysis and diaphysis (the long midsection of the long bone) lies the metaphysis, including the epiphyseal plate (growth plate). At the jo ...

or extremities 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 The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly 4 million people in five c ...

). Each of these compartments has its own

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

and nerve supply, and contains a different group of muscles. *

Medial fascial compartment of thigh The medial compartment of thigh is one of the fascial compartments of the thigh and contains the hip adductor muscles and the gracilis muscle. The obturator nerve is the primary nerve supplying this compartment. The obturator artery is the bloo ...

, adductor *

Posterior fascial compartment of thigh 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. Structure ...

, flexion,

hamstring In human anatomy, a hamstring () is any one of the three posterior thigh muscles in between the hip and the knee (from medial to lateral: semimembranosus, semitendinosus and biceps femoris). The hamstrings are susceptible to injury. In quadrupe ...

Anterior fascial compartment of thigh The anterior compartment of thigh contains muscles which extend the knee and flex the hip. Structure The anterior compartment is one of the fascial compartments of the thigh that contains groups of muscles together with their nerves and blood s ...

, extension Anterior compartment muscles of the thigh include sartorius, and the four muscles that comprise the

quadriceps muscles The quadriceps femoris muscle (, also called the quadriceps extensor, quadriceps or quads) is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the sole extensor muscle of the knee, forming a large ...

rectus femoris The rectus femoris muscle is one of the four quadriceps muscles of the human body. The others are the vastus medialis, the vastus intermedius (deep to the rectus femoris), and the vastus lateralis. All four parts of the quadriceps muscle attach ...

vastus medialis The vastus medialis (vastus internus or teardrop muscle) is an extensor muscle located medially in the thigh that extends the knee. The vastus medialis is part of the quadriceps muscle group. Structure The vastus medialis is a muscle present ...

vastus intermedius The vastus intermedius () (Cruraeus) arises from the front and lateral surfaces of the body of the femur in its upper two-thirds, sitting under the rectus femoris muscle and from the lower part of the lateral intermuscular septum. Its fibers en ...

and

vastus lateralis The vastus lateralis (), also called the vastus externus, is the largest and most powerful part of the quadriceps femoris, a muscle in the thigh. Together with other muscles of the quadriceps group, it serves to extend the knee joint, moving the ...

. Posterior compartment muscles of the thigh are the hamstring muscles, which include

semimembranosus The semimembranosus muscle () is the most medial of the three hamstring muscles in the thigh. It is so named because it has a flat tendon of origin. It lies posteromedially in the thigh, deep to the semitendinosus muscle. It extends the hip j ...

semitendinosus The semitendinosus () is a long superficial muscle in the back of the thigh. It is so named because it has a very long tendon of insertion. It lies posteromedially in the thigh, superficial to the semimembranosus. Structure The semitendinosus, r ...

, and

biceps femoris The biceps femoris () is a muscle of the thigh located to the posterior, or back. As its name implies, it has two parts, one of which (the long head) forms part of the hamstrings muscle group. Structure It has two heads of origin: *the ''long h ...

. Medial compartment muscles are pectineus,

adductor magnus Adductor may refer to: * One of the anatomical terms of motion Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminolo ...

adductor longus In the human body, the adductor longus is a skeletal muscle located in the thigh. One of the adductor muscles of the hip, its main function is to adduct the thigh and it is innervated by the obturator nerve. It forms the medial wall of the fem ...

and

adductor brevis The adductor brevis is a muscle in the thigh situated immediately deep to the pectineus and adductor longus. It belongs to the adductor muscle group. The main function of the adductor brevis is to pull the thigh medially. The 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 The femoral artery is a large artery in the thigh and the main arterial supply to the thigh and leg. The femoral artery gives off the deep femoral artery or profunda femoris artery and descends along the anteromedial part of the thigh in the f ...

and the

obturator artery The obturator artery is a branch of the internal iliac artery that passes antero-inferiorly (forwards and downwards) on the lateral wall of the pelvis, to the upper part of the obturator foramen, and, escaping from the pelvic cavity through the ob ...

. 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 cisterna chyli (or cysterna chyli, and etymologically more correct, receptaculum chyli) is a dilated sac at the lower end of the thoracic duct in most mammals into which lymph from the intestinal trunk and two lumbar lymphatic trunks flow. It ...

. The deep venous system of the thigh consists of the

femoral vein In the human body, the femoral vein is a blood vessel that accompanies the femoral artery in the femoral sheath. It begins at the adductor hiatus (an opening in the adductor magnus muscle) as the continuation of the popliteal vein. It ends a ...

, the proximal part of the

popliteal vein The popliteal vein is a vein of the lower limb. It is formed from the anterior tibial vein and the posterior tibial vein. It travels medial to the popliteal artery, and becomes the femoral vein. It drains blood from the leg. It can be assess ...

, and various smaller vessels; these are the site of proximal

deep venous thrombosis Deep vein thrombosis (DVT) is a type of venous thrombosis involving the formation of a blood clot in a deep vein, most commonly in the legs or pelvis. A minority of DVTs occur in the arms. Symptoms can include pain, swelling, redness, and enla ...

. The ''venae perfortantes'' connect the deep and the superficial system, which consists of the saphenous veins (the site of

varicose vein Varicose veins, also known as varicoses, are a medical condition in which superficial veins become enlarged and twisted. These veins typically develop in the legs, just under the skin. Varicose veins usually cause few symptoms. However, some indi ...

s).

Clinical significance

Thigh weakness can result in a positive Gowers' sign on physical examination. Regarding

Sports injury Sports injuries are injuries that occur during sport, athletic activities, or exercising. In the United States, there are approximately 30 million teenagers and children who participate in some form of organized sport. Of those, about three m ...

, whether

acute Acute may refer to: Science and technology * Acute angle ** Acute triangle ** Acute, a leaf shape in the glossary of leaf morphology * Acute (medicine), a disease that it is of short duration and of recent onset. ** Acute toxicity, the adverse eff ...

or from overuse, a thigh injury can mean significant incapacity to perform.

Soft tissue injury A soft tissue injury is the damage of muscles, ligaments and tendons throughout the body. Common soft tissue injuries usually occur from a sprain, strain, a one-off blow resulting in a contusion or overuse of a particular part of the body. Soft ti ...

can encompass

sprains A sprain, also known as a torn ligament, is an acute soft tissue injury of the ligaments within a joint, often caused by a sudden movement abruptly forcing the joint to exceed its functional range of motion. Ligaments are tough, inelastic fibers ...

, strains,

bruising A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur clos ...

and

tendinitis Tendinopathy, a type of tendon disorder that results in pain, swelling, and impaired function. The pain is typically worse with movement. It most commonly occurs around the shoulder (rotator cuff tendinitis, biceps tendinitis), elbow (tennis elbo ...

. Runner's knee ( Patellofemoral pain): is a direct consequence of the kneecap rubbing against the end of the thigh bone (”

”). Tight hamstrings and weak thigh muscles, required to stabilize the knee, risk development of runner's knee.

Food

The thigh meat of some animals such as

chicken The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adu ...

and

cow Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult ma ...

is consumed as food in many parts of the world.

Society and culture

Western societies generally tolerate clothing that displays thighs, such as

short shorts "Short Shorts" is a song written and performed by Tom Austin, Bill Crandell, Bill Dalton, Russ Viers, and Bob Gaudio, members of The Royal Teens. It reached #2 on the U.S. R&B chart and #3 on the U.S. pop chart in 1958. The group originally rele ...

and

miniskirts A miniskirt (sometimes hyphenated as mini-skirt, separated as mini skirt, or sometimes shortened to simply mini) is a skirt with its hemline well above the knees, generally at mid-thigh level, normally no longer than below the buttocks; and a ...

Beachwear A swimsuit is an item of clothing designed to be worn by people engaging in a water-based activity or water sports, such as swimming, diving and surfing, or sun-orientated activities, such as sun bathing. Different types may be worn by men, wom ...

and many

athleisure Athleisure is a hybrid style of athletic clothing typically worn as everyday wear. Athleisure outfits can include yoga pants, tights, sneakers, leggings and shorts that look like athletic wear, characterized as "fashionable, dressed-up sweats a ...

styles often display thighs as well. Professional dress codes may require covering up bare thighs. Many

Islamic countries The terms Muslim world and Islamic world commonly refer to the Islamic community, which is also known as the Ummah. This consists of all those who adhere to the religious beliefs and laws of Islam or to societies in which Islam is practiced. In ...

disapprove of or prohibit the display of thighs, especially by women. Strategic covering or display of thighs is used in popular fashion around the world, such as thigh-high boots and '' zettai ryoiki''.

Additional images

Thigh muscles front.png, Front of thigh muscles from Gray's Anatomy of the human body from 1918. Thigh muscles back.png, Back thigh muscles of the gluteal and posterior femoral regions from Gray's Anatomy of the human body from 1918. Gray432.png, Cross-section through the middle of the thigh. File:Sobo 1909 573-574.png, Also showing major blood vessels and nerves. Thigh_cross_section.svg, Cross-section through the middle of the thigh. Gray436.png, The

Obturator externus The external obturator muscle, obturator externus muscle (; OE) is a flat, triangular muscle, which covers the outer surface of the anterior wall of the pelvis. It is sometimes considered part of the medial compartment of thigh, and sometimes c ...

References

{{Authority control Lower limb anatomy