Femur
| Bone: Femur | |
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| Anterior view of the femur | |
| Latin | os femoris, os longissimum |
| Gray's | subject #59 242 |
| Origins | Gastrocnemius , Vastus lateralis, Vastus medialis, Vastus intermedius |
| Insertions | tensor fasciae latae, gluteus medius, gluteus minimus, Gluteus maximus, Iliopsoas |
| Articulations | hip: acetabulum of pelvis superiorly knee: with the tibia and patella inferiorly |
| MeSH | Femur |
The femur (pl. femurs or femora), or thigh bone, is the most proximal (closest to the center of the body) bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in the rear legs. The femur is the largest bone in the body. The head of the femur articulates with the acetabulum. The femur is the strongest bone in the body, about as strong as steel.
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[edit] In humans
In human anatomy, the femur is the longest and largest bone in the body. The average adult male femur is 48 centimeters (18.9 in) in length and 2.8 cm (1.1 in) in diameter at the mid-shaft, and has the ability to support up to 30 times the weight of an adult.[1] The femur forms part of the hip joint (at the acetabulum) and part of the knee joint, above which it is located. There are four eminences, or protuberances, in the human femur: the head, the greater trochanter, the lesser trochanter, and the lower extremity. They appear at various times from just before birth to about age 14. Initially, they are joined to the main body of the femur with cartilage, which gradually becomes ossified until the protuberances become an integral part of the femur bone, usually in early adulthood.
The shaft of the femur is cylindrical and has a rough line, the linea aspera, on its posterior surface.
The intercondylar fossa is present between the condyles at the distal end of the femur. In addition to the intercondylar eminence on the tibial plateau, there is both an anterior and posterior intercondylar fossa (area), the sites of anterior cruciate and posterior cruciate ligament attachment, respectively.
[edit] Other species
In primitive tetrapods, the main points of muscle attachment along the femur are the internal trochanter and fourth trochanter, and a ridge along the ventral surface of the femoral shaft referred to as 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 is also often absent in mammals or alternatively reduced to a series of creases along the surface of the bone.[2]
Some species of whales[3], snakes, and other non-walking vertebrates have vestigial femurs.
One of the earliest known vertebrates to have a femur is the Eusthenopteron, a prehistoric lobe-finned fish from the Late Devonian period.
[edit] Terminology in invertebrate zoology
In invertebrate zoology 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, the prefemur, connects the trochanter and femur.
[edit] Fractures
A femoral fracture that involves the femoral head, femoral neck or the shaft of the femur immediately below the lesser trochanter may be classified as a hip fracture, especially when associated with osteoporosis.
[edit] Etymology
In medical Latin the genitive form of femur is always femoris, but in classical Latin the genitive is often feminis, and should not be confused with case forms of femina, which means "woman".
[edit] Additional images
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Knee diagram
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Upper extremity of right femur viewed from behind and above.
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Right femur. Anterior surface.
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Right femur. Posterior surface.
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Left hip-joint, opened by removing the floor of the acetabulum from within the pelvis.
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Right knee-joint. Posterior view.
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Left knee-joint from behind, showing interior ligaments.
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Sagittal section of right knee-joint.
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Capsule of right knee-joint (distended). Lateral aspect.
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Capsule of right knee-joint (distended). Posterior aspect.
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Cross-section through the middle of the thigh.
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Deep muscles of the medial femoral region.
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Posterior view.
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Anterior view.
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Superior epiphysis - anterior view
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Superior epiphysis - posterior view
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Inferior epiphysis - posterior view
[edit] References
- ^ "The longest human bone". http://thelongestlistofthelongeststuffatthelongestdomainnameatlonglast.com/long254.html. Retrieved 2009-01-23.
- ^ Romer, Alfred Sherwood; Parsons, Thomas S. (1977). The Vertebrate Body. Philadelphia, PA: Holt-Saunders International. pp. 204–205. ISBN 0-03-910284-X.
- ^ Struthers, John (January 1881). "The Bones, Articulations, and Muscles of the Rudimentary Hind-Limb of the Greenland Right-Whale (Balaena mysticetus)". Journal of Anatomy and Physiology (Anatomical Society of Great Britain and Ireland) 15(Pt 2) (Pt 2): i1–176. PMC 1310010. PMID 17231384. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1310010.
[edit] External links
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Look up femur or thighbone in Wiktionary, the free dictionary. |
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