Body of ischium

Bone: Body of ischium
Right hip bone. External surface. (Ischium is at bottom left.)
Capsule of hip-joint (distended). Posterior aspect.
Latin	corpus ossis ischii
Gray's	subject #57 235

The body of the ischium enters into and constitutes a little more than two-fifths of the acetabulum. “The ischium is located on the inferoposterior portion of the hip bone and the heavy body is marked with a prominent ischial spine.”

Surfaces

Its external surface forms part of the lunate surface of the acetabulum and a portion of the acetabular fossa.

Its internal surface is part of the wall of the lesser pelvis; it gives origin to some fibers of the Obturator internus.

Borders

Its anterior border projects as the posterior obturator tubercle.

From its posterior border there extends backward a thin and pointed triangular eminence, the ischial spine, more or less elongated in different subjects.

Above and below the spine

Above the spine is a large notch, the greater sciatic notch.

Below the spine is a smaller notch, the lesser sciatic notch.

Muscle Attachment

Muscles that Originate on the Body of the Ischium

• Deep transverse perineal muscle
  • The deep transverse perineal muscle supports pelvic viscera & fixes perineal body.
• Superficial transverse perinei muscle
  • The superficial transverse perinei muscle fixes the perineal body

Muscles that Insert on the Body of the Ischium

No muscles insert on the Body of the Ischium

Additional images

• 

  Right hip bone. Internal surface.

• 

  Left hip-joint, opened by removing the floor of the acetabulum from within the pelvis.

External links

• SUNY Labs 44:st-0723 - "The Male Pelvis: Hip Bone"

References

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 As such, some of the information contained within it may be outdated.