A costal facet is a site of connection between a

rib In vertebrate anatomy, ribs ( la, costae) are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the ches ...

and a

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

. The costal facets are located on the vertebrae that the rib articulates with. They are the

superior costal facet The superior costal facet (or superior costal fovea) is a site where a rib forms a joint with the top of a vertebra. Ribs connect to the thoracic vertebrae at two main points, the inferior and superior costal facets. These connection points are l ...

, the

inferior costal facet The inferior costal facet (or inferior costal fovea) is a site where a rib forms a joint with the inferior aspect of the body of a thoracic vertebra. In the adjacent picture, the arrow points to an inferior costal facet. The facets are named for ...

, and the

transverse costal facet The transverse costal facet (or transverse costal fovea) is one of the costal facets, a site where a rib forms a joint with the transverse process of a thoracic vertebra. References External links * - "The costovertebral joint The costoverteb ...

. Rib 1 only articulates with a

. A transverse costal facet is a facet on the transverse process of the vertebrae for articulation with the tubercle on the rib. The superior costal facet joins the rib to the top of a vertebra. The transverse costal facet joins the rib to the transverse process of a vertebra, and the inferior costal facet joins the rib to the lower part of the vertebra. The joints formed are known as the

costovertebral joint The costovertebral joints are the joints that connect the ribs to the vertebral column. The articulation of the head of the rib connects the head of the rib to the bodies of the thoracic vertebrae. Structure The costotransverse joint connects th ...

References

Bones of the thorax Joints {{musculoskeletal-stub