In anatomy , the thigh is the area between the hip ( pelvis ) and the knee . Anatomically, it is part of the lower limb .
100-421: 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 as an attachment site for all muscles in the thigh. The head of the femur articulates with the acetabulum in the pelvic bone forming
200-439: A lateral and medial border . These three bordes separates the shaft into three surfaces: One anterior , one medial and one lateral. Due to the vast musculature of the thigh the shaft can not be palpated . The third trochanter is a bony projection occasionally present on the proximal femur near the superior border of the gluteal tuberosity. When present, it is oblong, rounded, or conical in shape and sometimes continuous with
300-440: A bone experiences within long bones such as the femur . As far as short bones are concerned, trabecular alignment has been studied in the vertebral pedicle . Thin formations of osteoblasts covered in endosteum create an irregular network of spaces, known as trabeculae. Within these spaces are bone marrow and hematopoietic stem cells that give rise to platelets , red blood cells and white blood cells . Trabecular marrow
400-479: A long bone are separated by a growing zone of cartilage (the epiphyseal plate ). At skeletal maturity (18 to 25 years of age), all of the cartilage is replaced by bone, fusing the diaphysis and both epiphyses together (epiphyseal closure). In the upper limbs, only the diaphyses of the long bones and scapula are ossified. The epiphyses, carpal bones, coracoid process, medial border of the scapula, and acromion are still cartilaginous. The following steps are followed in
500-509: A mineralized organic matrix. The primary inorganic component of human bone is hydroxyapatite , the dominant bone mineral , having the nominal composition of Ca 10 (PO 4 ) 6 (OH) 2 . The organic components of this matrix consist mainly of type I collagen —"organic" referring to materials produced as a result of the human body—and inorganic components, which alongside the dominant hydroxyapatite phase, include other compounds of calcium and phosphate including salts. Approximately 30% of
600-419: A more fulfilling and healthier lifestyle. Bone is constantly being created and replaced in a process known as remodeling . This ongoing turnover of bone is a process of resorption followed by replacement of bone with little change in shape. This is accomplished through osteoblasts and osteoclasts. Cells are stimulated by a variety of signals , and together referred to as a remodeling unit. Approximately 10% of
700-457: A number of anatomical terms to describe the appearance, shape and function of bones. Other anatomical terms are also used to describe the location of bones . Like other anatomical terms, many of these derive from Latin and Greek . Some anatomists still use Latin to refer to bones. The term "osseous", and the prefix "osteo-", referring to things related to bone, are still used commonly today. Some examples of terms used to describe bones include
800-422: A number of chemical enzymes that either promote or inhibit the activity of the bone remodeling cells, controlling the rate at which bone is made, destroyed, or changed in shape. The cells also use paracrine signalling to control the activity of each other. For example, the rate at which osteoclasts resorb bone is inhibited by calcitonin and osteoprotegerin . Calcitonin is produced by parafollicular cells in
900-452: 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 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 ( femur ). Tight hamstrings and weak thigh muscles, required to stabilize
1000-529: A positive correlation between the adaptations of resistance training and bone density. While nutritional and pharmacological approaches may also improve bone health, the strength and balance adaptations from resistance training are a substantial added benefit. Weight-bearing exercise may assist in osteoblast (bone-forming cells) formation and help to increase bone mineral content. High-impact sports, which involve quick changes in direction, jumping, and running, are particularly effective with stimulating bone growth in
1100-419: A recent study, there was a strong correlation between calcium intake and BMD across a variety of diverse populations of children and adolescence ultimately coming to the conclusion that fundamentally, achieving optimal bone health is necessary for providing our youth with the ability to undergo hormonal changes as well. They found in a study of over 10,000 children ages 8-19 that in females, African Americans, and
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#17328527265831200-408: A smaller number of randomly oriented collagen fibers, but forms quickly; it is for this appearance of the fibrous matrix that the bone is termed woven . It is soon replaced by lamellar bone, which is highly organized in concentric sheets with a much lower proportion of osteocytes to surrounding tissue. Lamellar bone, which makes its first appearance in humans in the fetus during the third trimester,
1300-401: A strong nutritional plan with adequate amounts of Calcium sources can lead to strong bones but also can be a worth-while strategy into preventing further damage or degradation of bone stores as we age. The connection between Calcium intake & BMD and its effects on youth as a whole is a very world-wide issue and has been shown to affect different ethnicities in a variety of differing ways. In
1400-571: A variety of doctors, including rheumatologists for joints, and orthopedic surgeons, who may conduct surgery to fix broken bones. Other doctors, such as rehabilitation specialists may be involved in recovery, radiologists in interpreting the findings on imaging, and pathologists in investigating the cause of the disease, and family doctors may play a role in preventing complications of bone disease such as osteoporosis. Femur The femur ( / ˈ f iː m ər / ; pl. : femurs or femora / ˈ f ɛ m ər ə / ), or thigh bone ,
1500-416: A variety of shapes and sizes and have complex internal and external structures. They are lightweight yet strong and hard and serve multiple functions . Bone tissue (osseous tissue), which is also called bone in the uncountable sense of that word, is hard tissue , a type of specialised connective tissue . It has a honeycomb -like matrix internally, which helps to give the bone rigidity. Bone tissue
1600-456: A very low shear stress strength (51.6 MPa). This means that bone resists pushing (compressional) stress well, resist pulling (tensional) stress less well, but only poorly resists shear stress (such as due to torsional loads). While bone is essentially brittle , bone does have a significant degree of elasticity , contributed chiefly by collagen . Mechanically, bones also have a special role in hearing . The ossicles are three small bones in
1700-441: Is mineralized tissue of two types, cortical bone and cancellous bone . Other types of tissue found in bones include bone marrow , endosteum , periosteum , nerves , blood vessels and cartilage . In the human body at birth, approximately 300 bones are present. Many of these fuse together during development, leaving a total of 206 separate bones in the adult, not counting numerous small sesamoid bones . The largest bone in
1800-405: Is a deep depression bounded posteriorly by the intertrochanteric crest on the medial surface of the greater trochanter. The lesser trochanter is a cone-shaped extension of the lowest part of the femur neck. The two trochanters are joined by the intertrochanteric crest on the back side and by the intertrochanteric line on the front. A slight ridge is sometimes seen commencing about the middle of
1900-403: Is also often absent in mammals or alternatively reduced to a series of creases along the surface of the bone. Structures analogous to the third trochanter are present in mammals, including some primates. Some species of whales , snakes , and other non-walking vertebrates have vestigial femurs. In some snakes the protruding end of a pelvic spur , a vestigial pelvis and femur remnant which
2000-436: Is attached to the lower and front part of the medial wall of the fossa and the anterior cruciate ligament to an impression on the upper and back part of its lateral wall. The articular surface of the lower end of the femur occupies the anterior, inferior, and posterior surfaces of the condyles. Its front part is named the patellar surface and articulates with the patella ; it presents a median groove which extends downward to
2100-474: Is called "osteoid". Around and inside collagen fibrils calcium and phosphate eventually precipitate within days to weeks becoming then fully mineralized bone with an overall carbonate substituted hydroxyapatite inorganic phase. In order to mineralise the bone, the osteoblasts secrete alkaline phosphatase, some of which is carried by vesicles . This cleaves the inhibitory pyrophosphate and simultaneously generates free phosphate ions for mineralization, acting as
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#17328527265832200-418: Is composed of a network of rod- and plate-like elements that make the overall organ lighter and allow room for blood vessels and marrow. Trabecular bone accounts for the remaining 20% of total bone mass but has nearly ten times the surface area of compact bone. The words cancellous and trabecular refer to the tiny lattice-shaped units (trabeculae) that form the tissue. It was first illustrated accurately in
2300-474: Is greater than its antero-posterior (front to back). It consists of two oblong eminences known as the condyles . Anteriorly, the condyles are slightly prominent and are separated by a smooth shallow articular depression called the patellar surface. Posteriorly, they project considerably and a deep notch, the Intercondylar fossa of femur , is present between them. The lateral condyle is the more prominent and
2400-584: Is less common to see, the necessity for a healthy routine especially when it comes to bone development is essential in our youth. Children that naturally have lower bone mineral density have a lower quality of life and therefore lead a life that is less fulfilling and uncomfortable. Factors such as increases in Calcium intake has been shown to increase BMD stores. Studies have shown that increasing calcium stores whether that be through supplementation or intake via foods and beverages such as leafy greens and milk have pushed
2500-492: Is made up of different types of bone cells . Osteoblasts and osteocytes are involved in the formation and mineralisation of bone; osteoclasts are involved in the resorption of bone tissue. Modified (flattened) osteoblasts become the lining cells that form a protective layer on the bone surface. The mineralised matrix of bone tissue has an organic component of mainly collagen called ossein and an inorganic component of bone mineral made up of various salts. Bone tissue
2600-518: Is mostly found in the bone marrow of the femur, the ribs, the vertebrae and pelvic bones . Bone receives about 10% of cardiac output. Blood enters the endosteum , flows through the marrow, and exits through small vessels in the cortex. In humans, blood oxygen tension in bone marrow is about 6.6%, compared to about 12% in arterial blood, and 5% in venous and capillary blood. Bone is metabolically active tissue composed of several types of cells. These cells include osteoblasts , which are involved in
2700-527: Is necessary during our childhood as these factors lead to a supportive and healthy lifestyle/bone health. Up till the age of 30, the bone stores that we have will ultimately start to decrease as we surpass this age. Influencing factors that can help us have larger stores and higher amounts of BMD will allow us to see less harmful results as we reach older adulthood. The issue of having fragile bones during our childhood leads to an increase in certain disorders and conditions such as juvenile osteoporosis , though it
2800-458: Is not connected to the rest of the skeleton, plays a role in mating. This role in mating is hypothesized to have possibly occurred in Basilosauridae , an extinct family of whales with well-defined femurs, lower legs and feet. Occasionally, the genes that code for longer extremities cause a modern whale to develop miniature legs ( atavism ). One of the earliest known vertebrates to have a femur
2900-451: Is not fully known. Two types of bone can be identified microscopically according to the arrangement of collagen: woven and lamellar. Woven bone is produced when osteoblasts produce osteoid rapidly, which occurs initially in all fetal bones, but is later replaced by more resilient lamellar bone. In adults, woven bone is created after fractures or in Paget's disease . Woven bone is weaker, with
3000-403: Is not uniformly solid, but consists of a flexible matrix (about 30%) and bound minerals (about 70%), which are intricately woven and continuously remodeled by a group of specialized bone cells. Their unique composition and design allows bones to be relatively hard and strong, while remaining lightweight. Bone matrix is 90 to 95% composed of elastic collagen fibers, also known as ossein, and
3100-430: Is quite rough due to attachment of muscles and the hip joint capsule . Here the two trochanters , greater and lesser trochanter , are found. The greater trochanter is almost box-shaped and is the most lateral prominent of the femur. The highest point of the greater trochanter is located higher than the collum and reaches the midpoint of the hip joint . The greater trochanter can easily be felt. The trochanteric fossa
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3200-414: Is slightly arched, so as to be convex in front, and concave behind, where it is strengthened by a prominent longitudinal ridge, the linea aspera which diverges proximally and distal as the medial and lateral ridge. Proximally the lateral ridge of the linea aspera becomes the gluteal tuberosity while the medial ridge continues as the pectineal line . Besides the linea aspera the shaft has two other bordes;
3300-730: Is stimulated by the secretion of growth hormone by the pituitary , thyroid hormone and the sex hormones ( estrogens and androgens ). These hormones also promote increased secretion of osteoprotegerin. Osteoblasts can also be induced to secrete a number of cytokines that promote reabsorption of bone by stimulating osteoclast activity and differentiation from progenitor cells. Vitamin D , parathyroid hormone and stimulation from osteocytes induce osteoblasts to increase secretion of RANK- ligand and interleukin 6 , which cytokines then stimulate increased reabsorption of bone by osteoclasts. These same compounds also increase secretion of macrophage colony-stimulating factor by osteoblasts, which promotes
3400-561: Is stronger and filled with many collagen fibers parallel to other fibers in the same layer (these parallel columns are called osteons). In cross-section , the fibers run in opposite directions in alternating layers, much like in plywood , assisting in the bone's ability to resist torsion forces. After a fracture, woven bone forms initially and is gradually replaced by lamellar bone during a process known as "bony substitution". Compared to woven bone, lamellar bone formation takes place more slowly. The orderly deposition of collagen fibers restricts
3500-547: Is the Eusthenopteron , a prehistoric lobe-finned fish from the Late Devonian period. A recent study revealed that bone is a much richer source of persistent DNA viruses than earlier perceived. Besides Parvovirus 19 and hepatitis B virus, ten additional ones were discovered, namely several members of the herpes- and polyomavirus families, as well as human papillomavirus 31 and torque teno virus. In invertebrate zoology
3600-448: Is the osteon . Cancellous bone or spongy bone , also known as trabecular bone , is the internal tissue of the skeletal bone and is an open cell porous network that follows the material properties of biofoams . Cancellous bone has a higher surface-area-to-volume ratio than cortical bone and it is less dense . This makes it weaker and more flexible. The greater surface area also makes it suitable for metabolic activities such as
3700-404: Is the broader both in its antero-posterior and transverse diameters. The medial condyle is the longer and, when the femur is held with its body perpendicular, projects to a lower level. When, however, the femur is in its natural oblique position the lower surfaces of the two condyles lie practically in the same horizontal plane. The condyles are not quite parallel with one another; the long axis of
3800-416: Is the only bone in the thigh — the region of the lower limb between the hip and the knee . In many four-legged animals the femur is the upper bone of the hindleg . The top of the femur fits into a socket in the pelvis called the hip joint, and the bottom of the femur connects to the shinbone ( tibia ) and kneecap ( patella ) to form the knee. In humans the femur is the largest and thickest bone in
3900-410: Is used in popular fashion around the world, such as thigh-high boots and zettai ryoiki . 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, and enable mobility . Bones come in
4000-492: Is very minimal. Being able to consistently meet calcium needs while also engaging in weight-bearing exercise is essential for building a strong initial bone foundation at which to build upon. Being able to reach our daily value of 1300mg for ages 9-18 is becoming more and more necessary and as we progress in health, the chance that osteoporosis and other factors such as bone fragility or potential for stunted growth can be greatly reduced through these resources, ultimately leading to
4100-451: The adductor crest . The neck of the femur is generally minimal or absent in the most primitive forms, reflecting a simple attachment to the acetabulum. The greater trochanter was present in the extinct archosaurs , as well as in modern birds and mammals, being associated with the loss of the primitive sprawling gait. The lesser trochanter is a unique development of mammals, which lack both the internal and fourth trochanters. The adductor crest
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4200-452: 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; these 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 ). Thigh weakness can result in
4300-440: 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 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 epiphyses , the lower extremity and the upper extremity of femur , that articulate with adjacent bones in
4400-432: The intercondyloid fossa and two convexities, the lateral of which is broader, more prominent, and extends farther upward than the medial. Each condyle is surmounted by an elevation, the epicondyle . The medial epicondyle is a large convex eminence to which the tibial collateral ligament of the knee-joint is attached. At its upper part is the adductor tubercle and behind it is a rough impression which gives origin to
4500-724: The middle ear which are involved in sound transduction. The cancellous part of bones contain bone marrow . Bone marrow produces blood cells in a process called hematopoiesis . Blood cells that are created in bone marrow include red blood cells , platelets and white blood cells . Progenitor cells such as the hematopoietic stem cell divide in a process called mitosis to produce precursor cells. These include precursors which eventually give rise to white blood cells , and erythroblasts which give rise to red blood cells. Unlike red and white blood cells, created by mitosis, platelets are shed from very large cells called megakaryocytes . This process of progressive differentiation occurs within
4600-479: The osteonic canal . Volkmann's canals at right angles connect the osteons together. The columns are metabolically active, and as bone is reabsorbed and created the nature and location of the cells within the osteon will change. Cortical bone is covered by a periosteum on its outer surface, and an endosteum on its inner surface. The endosteum is the boundary between the cortical bone and the cancellous bone. The primary anatomical and functional unit of cortical bone
4700-454: The round ligament to the sides of the acetabular notch . The head of the femur is connected to the shaft through the neck or collum . The neck is 4–5 cm. long and the diameter is smallest front to back and compressed at its middle. The collum forms an angle with the shaft in about 130 degrees. This angle is highly variant. In the infant it is about 150 degrees and in old age reduced to 120 degrees on average. An abnormal increase in
4800-499: The temporal bone to be the strongest bone. The femur length on average is 26.74% of a person's height, a ratio found in both men and women and most ethnic groups with only restricted variation, and is useful in anthropology because it offers a basis for a reasonable estimate of a subject's height from an incomplete skeleton . The femur is categorised as a long bone and comprises a diaphysis (shaft or body ) and two epiphyses (extremities) that articulate with adjacent bones in
4900-420: The thyroid gland , and can bind to receptors on osteoclasts to directly inhibit osteoclast activity. Osteoprotegerin is secreted by osteoblasts and is able to bind RANK-L, inhibiting osteoclast stimulation. Osteoblasts can also be stimulated to increase bone mass through increased secretion of osteoid and by inhibiting the ability of osteoclasts to break down osseous tissue . Increased secretion of osteoid
5000-445: The 12-15 adolescent groups that at 2.6-2.8g/kg of body weight, they began to see a decrease in BMD. They elaborate on this by determining that this is strongly influenced by a lower baseline in calcium intake throughout puberty. Genetic factors have also been shown to influence lower acceptance of calcium stores. Ultimately, the window that youth have for accruing and building resilient bones
5100-420: The acellular component of bone consists of organic matter, while roughly 70% by mass is attributed to the inorganic phase. The collagen fibers give bone its tensile strength , and the interspersed crystals of hydroxyapatite give bone its compressive strength . These effects are synergistic . The exact composition of the matrix may be subject to change over time due to nutrition and biomineralization , with
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#17328527265835200-400: The angle is known as coxa valga and an abnormal reduction is called coxa vara . Both the head and neck of the femur is vastly embedded in the hip musculature and can not be directly palpated . In skinny people with the thigh laterally rotated, the head of the femur can be felt deep as a resistance profound (deep) for the femoral artery . The transition area between the head and neck
5300-469: The body is the femur or thigh-bone, and the smallest is the stapes in the middle ear . The Greek word for bone is ὀστέον (" osteon "), hence the many terms that use it as a prefix—such as osteopathy . In anatomical terminology , including the Terminologia Anatomica international standard, the word for a bone is os (for example, os breve , os longum , os sesamoideum ). Bone
5400-420: The body. The femur is the only bone in the upper leg . The two femurs converge medially toward the knees , where they articulate with the proximal ends of the tibiae . The angle of convergence of the femora is a major factor in determining the femoral-tibial angle . Human females have thicker pelvic bones , causing their femora to converge more than in males. In the condition genu valgum (knock knee)
5500-416: The bone marrow. After the cells are matured, they enter the circulation . Every day, over 2.5 billion red blood cells and platelets, and 50–100 billion granulocytes are produced in this way. As well as creating cells, bone marrow is also one of the major sites where defective or aged red blood cells are destroyed. Determined by the species, age, and the type of bone, bone cells make up to 15 percent of
5600-548: The bone matrix. The release of these growth factors from the bone matrix could cause the proliferation of osteoblast precursors. Essentially, bone growth factors may act as potential determinants of local bone formation. Cancellous bone volume in postmenopausal osteoporosis may be determined by the relationship between the total bone forming surface and the percent of surface resorption. A number of diseases can affect bone, including arthritis, fractures, infections, osteoporosis and tumors. Conditions relating to bone can be managed by
5700-429: The bone. Growth factor storage—mineralized bone matrix stores important growth factors such as insulin -like growth factors, transforming growth factor, bone morphogenetic proteins and others. Strong bones during our youth is essential for preventing osteoporosis and bone fragility as we age. The importance of insuring factors that could influence increases in BMD while lowering our risks for further bone degradation
5800-426: The breakdown of bones by the process of bone resorption . New bone is then formed by the osteoblasts. Bone is constantly remodeled by the resorption of osteoclasts and created by osteoblasts. Osteoclasts are large cells with multiple nuclei located on bone surfaces in what are called Howship's lacunae (or resorption pits ). These lacunae are the result of surrounding bone tissue that has been reabsorbed. Because
5900-458: The cartilage called "primary ossification centers". They mostly appear during fetal development, though a few short bones begin their primary ossification after birth . They are responsible for the formation of the diaphyses of long bones, short bones and certain parts of irregular bones. Secondary ossification occurs after birth and forms the epiphyses of long bones and the extremities of irregular and flat bones. The diaphysis and both epiphyses of
6000-447: The conversion of cartilage to bone: Bone development in youth is extremely important in preventing future complications of the skeletal system. Regular exercise during childhood and adolescence can help improve bone architecture, making bones more resilient and less prone to fractures in adulthood. Physical activity, specifically resistance training, stimulates growth of bones by increasing both bone density and strength. Studies have shown
6100-567: The creation and mineralization of bone tissue, osteocytes , and osteoclasts , which are involved in the reabsorption of bone tissue. Osteoblasts and osteocytes are derived from osteoprogenitor cells, but osteoclasts are derived from the same cells that differentiate to form macrophages and monocytes . Within the marrow of the bone there are also hematopoietic stem cells . These cells give rise to other cells, including white blood cells , red blood cells , and platelets . Osteoblasts are mononucleate bone-forming cells. They are located on
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#17328527265836200-641: The differentiation of progenitor cells into osteoclasts, and decrease secretion of osteoprotegerin. Bone volume is determined by the rates of bone formation and bone resorption. Certain growth factors may work to locally alter bone formation by increasing osteoblast activity. Numerous bone-derived growth factors have been isolated and classified via bone cultures. These factors include insulin-like growth factors I and II, transforming growth factor-beta, fibroblast growth factor, platelet-derived growth factor, and bone morphogenetic proteins. Evidence suggests that bone cells produce growth factors for extracellular storage in
6300-453: The engravings of Crisóstomo Martinez . Bone marrow , also known as myeloid tissue in red bone marrow, can be found in almost any bone that holds cancellous tissue . In newborns , all such bones are filled exclusively with red marrow or hematopoietic marrow, but as the child ages the hematopoietic fraction decreases in quantity and the fatty/ yellow fraction called marrow adipose tissue (MAT) increases in quantity. In adults, red marrow
6400-429: The exchange of calcium ions. Cancellous bone is typically found at the ends of long bones, near joints, and in the interior of vertebrae. Cancellous bone is highly vascular and often contains red bone marrow where hematopoiesis , the production of blood cells, occurs. The primary anatomical and functional unit of cancellous bone is the trabecula . The trabeculae are aligned towards the mechanical load distribution that
6500-414: 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 . These compartments are named the anterior , medial and posterior fascial compartments . A femoral fracture that involves the femoral head , femoral neck or the shaft of the femur immediately below
6600-422: The femurs converge so much that the knees touch one another. The opposite extreme is genu varum (bow-leggedness) . In the general population of people without either genu valgum or genu varum , the femoral-tibial angle is about 175 degrees. The femur is the largest and thickest bone in the human body. By some tested measures, it is also the strongest bone in the human body, whereas other strength tests show
6700-444: The first hyaline cartilage model of the femur is formed by chondrocytes . Endochondral ossification begins by the end of the embryonic period and primary ossification centers are present in all long bones of the limbs, including the femur, by the 12th week of development. The hindlimb development lags behind forelimb development by 1–2 days. As the femur is the only bone in the thigh, it serves as an attachment point for all
6800-410: The foci for calcium and phosphate deposition. Vesicles may initiate some of the early mineralization events by rupturing and acting as a centre for crystals to grow on. Bone mineral may be formed from globular and plate structures, and via initially amorphous phases. Five types of bones are found in the human body: long, short, flat, irregular, and sesamoid. In the study of anatomy , anatomists use
6900-410: The formation of bone from cartilage . Intramembranous ossification mainly occurs during formation of the flat bones of the skull but also the mandible, maxilla, and clavicles; the bone is formed from connective tissue such as mesenchyme tissue rather than from cartilage. The process includes: the development of the ossification center , calcification , trabeculae formation and the development of
7000-590: The formation of osteoid to about 1 to 2 μm per day. Lamellar bone also requires a relatively flat surface to lay the collagen fibers in parallel or concentric layers. The extracellular matrix of bone is laid down by osteoblasts , which secrete both collagen and ground substance. These cells synthesise collagen alpha polypetpide chains and then secrete collagen molecules. The collagen molecules associate with their neighbors and crosslink via lysyl oxidase to form collagen fibrils. At this stage, they are not yet mineralized, and this zone of unmineralized collagen fibrils
7100-423: The gluteal ridge. A structure of minor importance in humans, the incidence of the third trochanter varies from 17–72% between ethnic groups and it is frequently reported as more common in females than in males. The lower extremity of the femur (or distal extremity) is the thickest femoral extremity, the upper extremity is the shortest femoral extremity. It is somewhat cuboid in form, but its transverse diameter
7200-475: The groundwork for bone health later in life, reducing the risk of bone-related conditions such as osteoporosis. Bones have a variety of functions: Bones serve a variety of mechanical functions. Together the bones in the body form the skeleton . They provide a frame to keep the body supported, and an attachment point for skeletal muscles , tendons , ligaments and joints , which function together to generate and transfer forces so that individual body parts or
7300-444: The hip and knee. The upper or proximal extremity (close to the torso ) contains the head , neck , the two trochanters and adjacent structures. The upper extremity is the thinnest femoral extremity, the lower extremity is the thickest femoral extremity. The head of the femur , which articulates with the acetabulum of the pelvic bone , comprises two-thirds of a sphere . It has a small groove, or fovea , connected through
7400-402: 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
7500-437: The intertrochanteric crest, and reaching vertically downward for about 5 cm. along the back part of the body: it is called the linea quadrata (or quadrate line). About the junction of the upper one-third and lower two-thirds on the intertrochanteric crest is the quadrate tubercle located. The size of the tubercle varies and it is not always located on the intertrochanteric crest and that also adjacent areas can be part of
7600-442: The knee, increase the risk of developing of runner's knee. Western societies generally tolerate clothing that displays thighs, such as short shorts and miniskirts . Beachwear and many athleisure 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
7700-405: The lateral is almost directly antero-posterior, but that of the medial runs backward and medialward. Their opposed surfaces are small, rough, and concave, and form the walls of the intercondyloid fossa . This fossa is limited above by a ridge, the intercondyloid line , and below by the central part of the posterior margin of the patellar surface. The posterior cruciate ligament of the knee joint
7800-410: The lesser trochanter may be classified as a hip fracture , especially when associated with osteoporosis . Femur fractures can be managed in a pre-hospital setting with the use of a traction splint . In primitive tetrapods, the main points of muscle attachment along the femur are the internal trochanter and third trochanter , and a ridge along the ventral surface of the femoral shaft referred to as
7900-406: 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. 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
8000-418: The medial head of the gastrocnemius . The lateral epicondyle which is smaller and less prominent than the medial, gives attachment to the fibular collateral ligament of the knee-joint . The femur develops from the limb buds as a result of interactions between the ectoderm and the underlying mesoderm ; formation occurs roughly around the fourth week of development. By the sixth week of development,
8100-433: The muscles that exert their force over the hip and knee joints. Some biarticular muscles – which cross two joints, like the gastrocnemius and plantaris muscles – also originate from the femur. In all, 23 individual muscles either originate from or insert onto the femur. In cross-section, the thigh is divided up into three separate fascial compartments divided by fascia , each containing muscles. These compartments use
8200-499: The name femur appears in arthropodology . The usage is not homologous with that of vertebrate anatomy; the term "femur" simply has been adopted by analogy and refers, where applicable, to the most proximal of (usually) the two longest jointed segments of the legs of the arthropoda . The two basal segments preceding the femur are the coxa and trochanter . This convention is not followed in carcinology but it applies in arachnology and entomology . In myriapodology another segment,
8300-487: The notion that prepuberty or even early pubertal children will see increases in BMD with the addition of increase Calcium intake. Another research study goes on to show that long-term calcium intake has been proven to significantly contribute to overall BMD in children without certain conditions or disorders. This data shows that ensuring adequate calcium intake in children reinforces the structure and rate at which bones will begin to densify. Further detailing how structuring
8400-478: The osteoblast puts up collagen fibers. These collagen fibers are used as a framework for the osteoblasts' work. The osteoblast then deposits calcium phosphate which is hardened by hydroxide and bicarbonate ions. The brand-new bone created by the osteoblast is called osteoid . Once the osteoblast is finished working it is actually trapped inside the bone once it hardens. When the osteoblast becomes trapped, it becomes known as an osteocyte. Other osteoblasts remain on
8500-502: The osteoclasts are derived from a monocyte stem-cell lineage, they are equipped with phagocytic -like mechanisms similar to circulating macrophages . Osteoclasts mature and/or migrate to discrete bone surfaces. Upon arrival, active enzymes, such as tartrate-resistant acid phosphatase , are secreted against the mineral substrate. The reabsorption of bone by osteoclasts also plays a role in calcium homeostasis . Bones consist of living cells (osteoblasts and osteocytes) embedded in
8600-456: The osteocyte cell processes occupy channels called canaliculi. The many processes of osteocytes reach out to meet osteoblasts, osteoclasts, bone lining cells, and other osteocytes probably for the purposes of communication. Osteocytes remain in contact with other osteocytes in the bone through gap junctions—coupled cell processes which pass through the canalicular channels. Osteoclasts are very large multinucleate cells that are responsible for
8700-427: The periosteum. Endochondral ossification occurs in long bones and most other bones in the body; it involves the development of bone from cartilage. This process includes the development of a cartilage model, its growth and development, development of the primary and secondary ossification centers , and the formation of articular cartilage and the epiphyseal plates . Endochondral ossification begins with points in
8800-417: The quadrate tubercle, such as the posterior surface of the greater trochanter or the neck of the femur. In a small anatomical study it was shown that the epiphyseal line passes directly through the quadrate tubercle. The body of the femur (or shaft) is large, thick and almost cylindrical in form. It is a little broader above than in the center, broadest and somewhat flattened from before backward below. It
8900-684: The ratio of calcium to phosphate varying between 1.3 and 2.0 (per weight), and trace minerals such as magnesium , sodium , potassium and carbonate also be found. Type I collagen composes 90–95% of the organic matrix, with the remainder of the matrix being a homogenous liquid called ground substance consisting of proteoglycans such as hyaluronic acid and chondroitin sulfate , as well as non-collagenous proteins such as osteocalcin , osteopontin or bone sialoprotein . Collagen consists of strands of repeating units, which give bone tensile strength, and are arranged in an overlapping fashion that prevents shear stress. The function of ground substance
9000-462: The remainder is ground substance . The elasticity of collagen improves fracture resistance. The matrix is hardened by the binding of inorganic mineral salt, calcium phosphate , in a chemical arrangement known as bone mineral , a form of calcium apatite . It is the mineralization that gives bones rigidity. Bone is actively constructed and remodeled throughout life by special bone cells known as osteoblasts and osteoclasts. Within any single bone,
9100-578: The skeletal mass of an adult is remodelled each year. The purpose of remodeling is to regulate calcium homeostasis , repair microdamaged bones from everyday stress, and to shape the skeleton during growth. Repeated stress, such as weight-bearing exercise or bone healing, results in the bone thickening at the points of maximum stress ( Wolff's law ). It has been hypothesized that this is a result of bone's piezoelectric properties, which cause bone to generate small electrical potentials under stress. The action of osteoblasts and osteoclasts are controlled by
9200-469: The surface of osteon seams and make a protein mixture known as osteoid , which mineralizes to become bone. The osteoid seam is a narrow region of a newly formed organic matrix, not yet mineralized, located on the surface of a bone. Osteoid is primarily composed of Type I collagen . Osteoblasts also manufacture hormones , such as prostaglandins , to act on the bone itself. The osteoblast creates and repairs new bone by actually building around itself. First,
9300-450: The term "foramen" to describe a hole through which something passes, and a "canal" or "meatus" to describe a tunnel-like structure. A protrusion from a bone can be called a number of terms, including a "condyle", "crest", "spine", "eminence", "tubercle" or "tuberosity", depending on the protrusion's shape and location. In general, long bones are said to have a "head", "neck", and "body". When two bones join, they are said to "articulate". If
9400-459: 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
9500-419: The tissue is woven into two main patterns, known as cortical and cancellous bone, each with a different appearance and characteristics. The hard outer layer of bones is composed of cortical bone , which is also called compact bone as it is much denser than cancellous bone. It forms the hard exterior (cortex) of bones. The cortical bone gives bone its smooth, white, and solid appearance, and accounts for 80% of
9600-417: The top of the new bone and are used to protect the underlying bone, these become known as bone lining cells. Osteocytes are cells of mesenchymal origin and originate from osteoblasts that have migrated into and become trapped and surrounded by a bone matrix that they themselves produced. The spaces the cell body of osteocytes occupy within the mineralized collagen type I matrix are known as lacunae , while
9700-412: The total bone mass of an adult human skeleton . It facilitates bone's main functions—to support the whole body, to protect organs, to provide levers for movement, and to store and release chemical elements, mainly calcium. It consists of multiple microscopic columns, each called an osteon or Haversian system. Each column is multiple layers of osteoblasts and osteocytes around a central canal called
9800-418: The two bones have a fibrous connection and are relatively immobile, then the joint is called a "suture". The formation of bone is called ossification . During the fetal stage of development this occurs by two processes: intramembranous ossification and endochondral ossification . Intramembranous ossification involves the formation of bone from connective tissue whereas endochondral ossification involves
9900-430: The whole body can be manipulated in three-dimensional space (the interaction between bone and muscle is studied in biomechanics ). Bones protect internal organs, such as the skull protecting the brain or the ribs protecting the heart and lungs . Because of the way that bone is formed, bone has a high compressive strength of about 170 MPa (1,700 kgf/cm ), poor tensile strength of 104–121 MPa, and
10000-421: The youth. Sports such as soccer, basketball, and tennis have shown to have positive effects on bone mineral density as well as bone mineral content in teenagers. Engaging in physical activity during childhood years, particularly in these high-impact osteogenic sports, can help to positively influence bone mineral density in adulthood. Children and adolescents who participate in regular physical activity will place
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