Ilium (bone)

Ilium (bone)
Bone: Ilium of pelvis
Pelvis diagram.png
Overview of Ilium as largest bone of the pelvis.
Gray343.png
Capsule of hip-joint (distended). Posterior aspect. (Ilium labeled at top.)
Latin os ilii
Gray's subject #57 236
MeSH Ilium

The ilium is the uppermost and largest bone of the pelvis, and appears in most vertebrates including mammals and birds, but not bony fish. All reptiles have an ilium except snakes, although some snake species have a tiny bone which is considered to be an ilium.[1]

The name comes from the Latin (ile, ilis), meaning "groin" or "flank."[2]

The ilium of the human is divisible into two parts, the body and the ala; the separation is indicated on the top surface by a curved line, the arcuate line, and on the external surface by the margin of the acetabulum.

Contents

Body (corpus oss. ilii)

The body enters into the formation of the acetabulum, of which it forms rather less than two-fifths.

Its external surface is partly articular, partly non-articular; the articular segment forms part of the lunate surface of the acetabulum, the non-articular portion contributes to the acetabular fossa.

The internal surface of the body is part of the wall of the lesser pelvis and gives origin to some fibers of the Obturator internus.

Below, it is continuous with the pelvic surfaces of the ischium and pubis, only a faint line indicating the place of union.

Ala (ala oss. ilii)

The wing of ilium (or ala) is the large expanded portion which bounds the greater pelvis laterally. It presents for examination two surfaces—an external and an internal—a crest, and two borders—an anterior and a posterior.

Biiliac width

In humans, biiliac width is an anatomical term referring to the widest measure of the pelvis between the outer edges of the upper iliac bones.

Biiliac width has the following common synonyms: pelvic bone width, biiliac breadth, intercristal breadth/width, bi-iliac breadth/width and biiliocristal breadth/width.

In the average adult female, it measures 28 cm (11 in).[citation needed] It is best measured by anthropometric calipers (an anthropometer designed for such measurement is called a pelvimeter). Attempting to measure biiliac width with a tape measure along a curved surface is inaccurate.

The biiliac width measure is helpful in obstetrics because a pelvis that is significantly too small or too large can have obstetrical complications. For example, a large baby or a small pelvis often lead to death unless a caesarean section is performed. [3]

It is also used by anthropologists to estimate body mass.[4]

In dinosaurs

The clade Dinosauria is divided into the Saurischia and Ornithischia based on hip structure, including importantly that of the ilium.[5]

See also

Additional images

References

  1. ^ Jacobson, Elliott R. (2007). Infectious Diseases and Pathology of Reptiles. CRC Press. p. 7. ISBN 0849323215, 9780849323218. http://books.google.com/?id=hhO4WAZcVLEC&pg=PA7&lpg=PA7&dq=%22ilium%22+%22in+snakes%22. Retrieved 2009-01-09. 
  2. ^ Taber, Clarence Wilbur; Venes, Donald (2005). Taber's cyclopedic medical dictionary. Philadelphia: F.A. Davis. ISBN 0-8036-1207-9. 
  3. ^ "Encyclopedia of Medicine: Cesarean Section". eNotes. http://health.enotes.com/medicine-encyclopedia/cesarean-section. 
  4. ^ Ruff C, Niskanenb M, Junnob J, Jamisonc P (2005). "Body mass prediction from stature and bi-iliac breadth in two high latitude populations, with application to earlier higher latitude humans". Journal of Human Evolution 48 (4): 381–392. doi:10.1016/j.jhevol.2004.11.009. PMID 15788184. http://www.hopkinsmedicine.org/FAE/CBRMNJAPJ2005JHE.pdf. Retrieved 2006-07-26. 
  5. ^ Seeley, H.G. (1888). "On the classification of the fossil animals commonly named Dinosauria." Proceedings of the Royal Society of London, 43: 165-171.

External links

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.


Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Bone — is the substance that forms the skeleton of the body. It is composed chiefly of calcium phosphate and calcium carbonate. It also serves as a storage area for calcium, playing a large role in calcium balance in the blood. The 206 bones in the body …   Medical dictionary

  • Bone marrow — Simplified illustration of cells in bone marrow. Latin medulla ossium Code TA …   Wikipedia

  • Ilium — Il i*um, n. [See {Ileum}.] (Anat.) The dorsal one of the three principal bones comprising either lateral half of the pelvis; the dorsal or upper part of the hip bone. See {Innominate bone}, under {Innominate}. [Written also {ilion}, and {ileum}.] …   The Collaborative International Dictionary of English

  • ilium — (n.) pelvic bone, 1706, Modern Latin, from L. ilia (pl.) groin, flank (see ILEUM (Cf. ileum)) …   Etymology dictionary

  • ilium — ► NOUN (pl. ilia) ▪ the large broad bone forming the upper part of each half of the pelvis. ORIGIN Latin, singular of ilia flanks, entrails …   English terms dictionary

  • ilium — [il′ē əm] n. pl. ilia [il′ēə] [ModL: see ILEUM] the flat, uppermost portion of the three sections of the innominate bone …   English World dictionary

  • Bone — This article is about the skeletal organ. For other uses, see Bone (disambiguation) and Bones (disambiguation). For the tissue, see Osseous tissue. Drawing of a human femur Bones are rigid organs that constitute part of the endoskeleton of… …   Wikipedia

  • ilium — The broad, flaring portion of the hip bone, distinct at birth but later becoming fused with the ischium and pubis; it consists of a body, which joins the pubis and ischium to form the acetabulum and a broad thin portion, called the ala or …   Medical dictionary

  • ilium — Ileum Il e*um, n. [L. ile, ileum, ilium, pl. ilia, groin, flank.] 1. (Anat.) The last, and usually the longest, division of the small intestine; the part between the jejunum and large intestine. [Written also {ileon}, and {ilium}.] [1913 Webster] …   The Collaborative International Dictionary of English

  • bone — I (New American Roget s College Thesaurus) n. whalebone, ivory, etc. See density, body. II (Roget s IV) n. Syn. skeletal substance, osseous matter, bony process, bone cartilage, ossein. Bones of the human skeleton include: cranium or skull,… …   English dictionary for students

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”