Costovertebral Joints:

1. The inferior facet on the head of each of ribs 2 - 9 articulates with the superior demi-facet on the body of the corresponding vertebra. The superior facet articulates with the inferior demi-facet of the vertebrae above.

2. The crest of the rib articulates with the intervertebral disc by the intra-articular ligament of the head of the rib.

3. The heads of ribs 1, 10 (usually), 11, and 12 have a rounded head with a single articular facet that articulates only with the corresponding vertebra. These joints are all synovial.

Costotransverse Joints:

1. The tubercles of the first ten ribs form synovial joints with the facets of the transverse processes of the corresponding vertebrae. Strong costotransverse ligaments unite each rib and vertebra.

2. The spinal nerves and posterior branches of the intercostal artery exit between the apertures that are formed by the superior costotranverse ligament and the body of the vertebra.

The double articulation of each rib with the bodies of two vertebrae and the transverse process of its corresponding vertebra and the relative positions of these attachments means that the ribs twist on their articulations rather than slide up and down.