Dens (anatomy)

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Dens (anatomy)

Second cervical vertebra, or epistropheus, from above. (Dens labeled at center top.)

Second cervical vertebra, epistropheus, or axis, from the side. (Odontoid process labeled at center top.)
Gray's	subject #21 99
Dorlands/Elsevier	d_08/12285795

The dens or odontoid process of the axis exhibits a slight constriction or neck, where it joins the body.

On its anterior surface is an oval or nearly circular facet for articulation with that on the anterior arch of the atlas.

On the back of the neck, and frequently extending on to its lateral surfaces, is a shallow groove for the transverse atlantal ligament which retains the process in position.

The apex is pointed, and gives attachment to the apical odontoid ligament; below the apex the process is somewhat enlarged, and presents on either side a rough impression for the attachment of the alar ligament; these ligaments connect the process to the occipital bone.

The internal structure of the odontoid process is more compact than that of the body.

Dens is also another word for 'teeth', hence the name 'DENTIST'.

[edit] Additional images

Sagittal section of nose mouth, pharynx, and larynx.

[edit] External links

MeSH Odontoid+process
Diagram at umich.edu (Odontoid process is #3)
Atlas of anatomy at UMich back_bone11 - "C2, 2nd Cervical Vertebra or Axis - Superior View (Dens is #1)"
Atlas of anatomy at UMich back_bone12 - "C2, 2nd Cervical Vertebra or Axis - Posterior View (Dens is #1)"
SUNY Labs 31:st-0204 - "Pharynx - Bones"

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.