Dorsal surface of sacrum

Dorsal surface of sacrum
Bone: Dorsal surface of sacrum
Gray96.png
Sacrum, dorsal surface.
Latin facies dorsalis ossis sacri
Gray's subject #24 107

The dorsal surface of sacrum is convex and narrower than the pelvic.

In the middle line it displays a crest, the middle sacral crest, surmounted by three or four tubercles, the rudimentary spinous processes of the upper three or four sacral vertebrae.

On either side of the middle sacral crest is a shallow groove, the sacral groove, which gives origin to the multifidus, the floor of the groove being formed by the united laminae of the corresponding vertebrae.

The laminae of the fifth sacral vertebra, and sometimes those of the fourth, fail to meet behind, and thus a hiatus or deficiency occurs in the posterior wall of the sacral canal.

On the lateral aspect of the sacral groove is a linear series of tubercles produced by the fusion of the articular processes which together form the indistinct sacral articular crests.

The articular processes of the first sacral vertebra are large and oval in shape; their facets are concave from side to side, look backward and medialward, and articulate with the facets on the inferior processes of the fifth lumbar vertebra.

The tubercles which represent the inferior articular processes of the fifth sacral vertebra are prolonged downward as rounded processes, which are named the sacral cornua, and are connected to the cornua of the coccyx.

Lateral to the articular processes are the four posterior sacral foramina; they are smaller in size and less regular in form than the anterior, and transmit the posterior divisions of the sacral nerves.

On the lateral side of the posterior sacral foramina is a series of tubercles, which represent the transverse processes of the sacral vertebrae, and form the lateral crests of the sacrum.

The transverse tubercles of the first sacral vertebra are large and very distinct; they, together with the transverse tubercles of the second vertebra, give attachment to the horizontal parts of the posterior sacroiliac ligaments; those of the third vertebra give attachment to the oblique fasciculi of the posterior sacroiliac ligaments; and those of the fourth and fifth to the sacrotuberous ligaments.

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 As such, some of the information contained within it may be outdated.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

Look at other dictionaries:

  • dorsal surface of sacrum — facies dorsalis ossis sacri …   Medical dictionary

  • Sacrum — For other uses, see Sacrum (disambiguation). Not to be confused with cecum. Bone: Sacrum Sacrum, pelvic surface …   Wikipedia

  • surface — The outer part of any solid. SYN: face (2) [TA], facies (2) [TA]. [F. fr. L. superficius, see superficial] acromial articular s. of clavicle SYN: acromial facet of clavicle. anterior s. [TA] the s. of a …   Medical dictionary

  • Facies — A direct borrowing from the Latin, facies means face. * * * 1. [TA] SYN: face (1). 2. [NA] SYN: surface. 3. SYN: expression (2). [L.] acromial articular f. of clavicle SYN: acromial facet of clavicle. adenoid f. the open mouthed and often …   Medical dictionary

  • facies dorsalis ossis sacri — [TA] dorsal surface of sacrum: the markedly convex and rough posterior surface of the sacral bone, which gives origin to the sacrospinalis and multifidus muscles; called also posterior surface of sacrum …   Medical dictionary

  • Muscle — is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart… …   Medical dictionary

  • Ligament — A ligament is a tough band of connective tissue that connects various structures such as two bones. Ligament is a fitting term; it comes from the Latin ligare meaning to bind or tie. * * * 1. A band or sheet of fibrous tissue connecting two or… …   Medical dictionary

  • List of muscles of the human body — Skeletal muscles homo sapiens Muscles of the human body: Overview Head  |  Neck  |&# …   Wikipedia

  • 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

  • Median sacral crest — Bone: Median sacral crest Sacrum, dorsal surface …   Wikipedia

Share the article and excerpts

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

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.