This is consistent with Terminologia Anatomica , which solely employs the thoracic designator to refer to this part of the spine. However, in French-speaking parts of the world, D1-D12 are commonly used interchangeably with T1-T12 7. The superior demifacet of a thoracic vertebra articulates with the corresponding rib costovertebral joint.
This rib articulates again with the costal facet on the transverse process costotransverse joint. The inferior demifacet articulates with the rib below. For example, the superior demifacet and costal facet on the transverse process of T5 will articulate with the fifth rib.
The inferior demifacet of T5 will articulate with the sixth rib. The superior articular process arises from the upper border of the pedicle. An oval facet faces posterolaterally. The inferior articular process arises from the lower border of the pedicle. The facet faces anteromedially. Similar to other vertebrae, discs are interposed between hyaline cartilage on the centrum of the vertebral bodies.
The disc height is slightly less than cervical vertebrae. Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. Updating… Please wait. Unable to process the form.
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On this page:. Quiz questions. Typical thoracic vertebrae have several features distinct from those typical of cervical or lumbar vertebrae. The primary characteristic of the thoracic vertebrae is the presence of costal facets.
There are six facets per thoracic vertebrae: two on the transverse processes and four demifacets—the facets of the transverse processes articulate with the tubercle of the associated rib. The demifacets are bilaterally paired and located on the superior and inferior posterolateral aspects of the vertebrae. They are positioned so that the superior demifacet of the inferior vertebrae articulates with the head of the same rib that articulates with the inferior demifacet of the superior rib.
For example, the inferior demifacets of T4 and the superior demifacets of T5 articulate with the head of rib 5. The length of the transverse processes decreases as the column descends. The positioning of the ribs and spinous processes greatly limits flexion and extension of the thoracic vertebrae. However, T5-T8 have the greatest rotation ability of the thoracic region.
Thoracic vertebrae have superior articular facets that face in a posterolateral direction. The spinous process is long, relative to other regions, and is directed posteroinferiorly. This projection gradually increases as the column descends before decreasing rapidly from T9-T The intervertebral disc height is, on average, the least of the vertebral regions. They alone articulate with the first rib; C7 has no costal facets.
T1 does, however, have typical inferior demifacets for articulation with the second rib. T1 also has a long, almost horizontal spinous process, similar to a cervical vertebra that may be as long as the vertebra prominens of C7.
They also lack facets on the transverse processes. It varies by individual, but T10 may resemble the atypical nature of the 11 and 12 vertebrae. When that is the case, T9 lacks an inferior demifacet, as it would not be needed to articulate with the 10th rib.
Additionally, T12 is unique in that it represents a transition from the thoracic to the lumbar vertebra. It is thoracic in that it contains costal facets and superior articular facets that allow for rotation, flexion, and rotation. It is lumbar in that it has articular processes that do not allow for rotation, only flexion, and extension.
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