What makes up the os coxae

It consists of three parts, the ilium, ischium, and pubis, which are distinct from each other in the young subject, but are fused in the adult; the union of the three parts takes place in and around a large cup-shaped articular cavity, the acetabulum, which is situated near the middle of the outer surface of the bone.

The ilium, so-called because it supports the flank, is the superior broad and expanded portion which extends upward from the acetabulum. The ischium is the lowest and strongest portion of the bone; it proceeds downward from the acetabulum, expands into a large tuberosity, and then, curving forward, forms, with the pubis, a large aperture, the obturator foramen.

The pubis extends medialward and downward from the acetabulum and articulates in the middle line with the bone of the opposite side: it forms the front of the pelvis and supports the external organs of generation. IMAIOS and selected third parties, use cookies or similar technologies, in particular for audience measurement. Cookies allow us to analyze and store information such as the characteristics of your device as well as certain personal data e. For more information, see our privacy policy.

You can freely give, refuse or withdraw your consent at any time by accessing our cookie settings tool. It is comprised of the iliopubic ramus , the ischiopubic ramus , and the pubic symphisis.

The two rami are named for the portions of the os coxa to which they connect. These rami form the superior and inferior margins of the obturator foramen.

The rami converge ventrally, where they meet the pubic symphisis, the roughened surface where the os coxae meet. Sex Determination. Due largely to the demands placed on females during the process of birth, the os coxa is one of the most sexually dimorphic bones in the body. Because females are on average smaller in body size than males, the female os coxa is generally smaller than that of males. However, the female os coxa exhibits several differences compared with males, mostly related to maximizing the dimensions of the birth canal.

The superior opening, or aperture, of the articulated pelvis is generally heart-shaped in males, while in females it is larger and more rounded. The female ilium has more laterally flared blades than the male ilium. The greater sciatic notch is much more open in females, while it is more constricted in males.

Age Estimation. The morphology of the pubic symphisis has proven to be a relatively reliable age indicator. About MyAccess If your institution subscribes to this resource, and you don't have a MyAccess Profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Learn More. Sign in via OpenAthens. Sign in via Shibboleth. AccessBiomedical Science. AccessEmergency Medicine. Case Files Collection. Clinical Sports Medicine Collection. Davis AT Collection. Davis PT Collection. Murtagh Collection. About Search. Enable Autosuggest. You have successfully created a MyAccess Profile for alertsuccessName. Previous Chapter. Next Chapter. Morton D. David A. Morton, et al. The Big Picture: Gross Anatomy, 2e.

McGraw Hill; The pelvic girdle Information The pelvic girdle is name given the left and right coxal bones. Figure The three bones of an unfused coxal bone.

The right coxal bone. Lab 7 Exercises 7. You can describe any features on the bone and which direction it has to face to allow you to determine whether that particular bone came from anatomical left or anatomical right.