anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

, the thigh is the area between the hip (

pelvis The pelvis (: pelves or pelvises) is the lower part of an Anatomy, anatomical Trunk (anatomy), trunk, between the human abdomen, abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also c ...

) and the

knee In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the hu ...

. Anatomically, it is part of the

lower limb Lower may refer to: *Lower (album), ''Lower'' (album), 2025 album by Benjamin Booker *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Gloucestershire, England See also

*Nizhny {{Disambiguation ...

. 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 (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femo ...

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

bone tissue A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provi ...

), and forms a

ball and socket joint The ball-and-socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around an indefinite number of ...

at the hip, and a modified

hinge joint A hinge joint (ginglymus or ginglymoid) is a bone joint where the articular surfaces are molded to each other in such a manner as to permit motion only in one plane. According to one classification system they are said to be uniaxial (having o ...

at the knee.

Structure

Bones

The

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 The acetabulum (; : acetabula), also called the cotyloid cavity, is a wikt:concave, concave surface of the pelvis. The femur head, head of the femur meets with the pelvis at the acetabulum, forming the Hip#Articulation, hip joint. Structure The ...

in the pelvic bone forming the

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

, while the distal part of the femur articulates with the

tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...

and patella forming the

. By most measures, the femur is the strongest and longest bone in the body. The femur is categorised as a

long bone The long bones are those that are longer than they are wide. They are one of five types of bones: long, short, flat, irregular and sesamoid. Long bones, especially the femur and tibia, are subjected to most of the load during daily activities ...

and comprises a

diaphysis The diaphysis (: diaphyses) 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 centr ...

, 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 A fascia (; : fasciae or fascias; adjective fascial; ) is a generic term for macroscopic membranous bodily structures. Fasciae are classified as superficial, visceral or deep, and further designated according to their anatomical location. ...

, each containing muscles. These compartments use the femur as an axis and are separated by tough

connective tissue Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesod ...

membranes (or

septa SEPTA, the Southeastern Pennsylvania Transportation Authority, is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly four million people througho ...

). 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 is com ...

and

nerve A nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the Electrochemistry, electrochemical nerv ...

supply, and contains a different group of

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

s. * Medial fascial compartment of thigh, adductor * Posterior fascial compartment of thigh, flexion,

hamstring A hamstring () is any one of the three posterior thigh muscles in human anatomy between the hip and the knee: from medial to lateral, the semimembranosus, semitendinosus and biceps femoris. Etymology The word " ham" is derived from the Old ...

* 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 The adductor magnus is a large triangular muscle, situated on the medial side of the thigh. It consists of two parts. The portion which arises from the ischiopubic ramus (a small part of the inferior ramus of the pubis, and the inferior ramu ...

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 Adduction, adduct the thigh and it is innervated by the obturator nerve. It forms the medial wall ...

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 brevi ...

, 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

Common femoral and subsartorial artery and vein

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 and descends along the anteromedial part of the thigh in the femoral triangle. It enters ...

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

, common femoral vein, deep femoral vein, the proximal part of the popliteal vein, and various smaller vessels; these are the site of proximal

deep vein 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 enl ...

. The perforating veins connect the deep and the superficial system, which consists of the

small Small means of insignificant size Size in general is the Magnitude (mathematics), magnitude or dimensions of a thing. More specifically, ''geometrical size'' (or ''spatial size'') can refer to three geometrical measures: length, area, or ...

and

great saphenous vein The great saphenous vein (GSV; ) or long saphenous vein is a large, subcutaneous, superficial vein of the human leg, leg. It is the longest vein in the body, running along the length of the lower limb, returning blood from the foot, human leg, le ...

s (the site of varicose veins).

Clinical significance

Thigh weakness can result in a positive Gowers' sign on physical examination. Thigh injury resulting from sports, whether acute or from overuse, 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 (injury), strain, a one-off blow resulting in a contusion or overuse of a particular part of ...

can encompass sprains, strains, bruising and tendinitis. 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, increase the risk of developing of runner's knee.

Society and culture

Western societies generally tolerate clothing that displays thighs, such as short shorts and miniskirts. Beachwear and many

athleisure Athleisure is a hybrid style of athletic clothing typically worn as everyday wear. The word is a portmanteau combining the words 'athletic' and 'leisure'. Athleisure outfits can include tracksuits, sports jackets, hoodies, yoga pants, tight ...

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

References

{{Authority control Lower limb anatomy