Which of the following statements correctly describes the articulation of the head of the fifth rib with the thoracic spine?

a. The superior facet of the fifth rib articulates with the vertebral body of its own level (T5); the inferior facet articulates with the vertebral body below (T6).
b. The fifth rib has a single facet and only articulates with the vertebral body of its own level (T5).
c. The superior facet articulates with the vertebral body above (T4); the inferior facet of the fifth rib articulates with the vertebral body of its own level (T5).
d. The fifth rib articulates with the vertebral body and transverse process of the vertebrae of its own level.

ANS: C
In the costovertebral joint, the head of the rib articulates with two vertebrae and the vertebral disc
between them. Each rib has two articular facets referred to as demifacets. The superior demifacet
articulates with the vertebral body above and the inferior demifacet articulates with the vertebral
body of the corresponding level to the rib. A crest, which separates the two facets, articulates with
the intervertebral disc between the two vertebral bodies.