where does the head of the rib attach
Rib cage Each rib consists of a head, neck, and a shaft, and they are numbered from top to bottom. The head of a rib is the end part closest to the spine with which it articulates. It is marked by a kidney-shaped articular surface which is divided by a horizontal crest into two facets. The superior facet is smaller and articulates with the vertebra above, and the inferior facet articulates with the vertebra of the same number. The transverse process of a thoracic vertebra also articulates with the rib of the same number. The crest gives attachment to the intra-articular ligament.[3] All ribs are attached posteriorly to the thoracic vertebrae.
Rib Humans have 24 ribs (12 pairs). The first seven sets of ribs, known as "true ribs" (costae verae) also known as vertebrosternal ribs, are directly attached to the sternum through the costal cartilage. Rib 1 is unique and harder to distinguish than other ribs. It is a short, flat, C-shaped bone. The vertebral attachment can be found just below the neck and the majority of this bone can be found above the level of the clavicle. Ribs 2 through 7 have a more traditional appearance and become longer and less curved as they progress downwards.[1] The following five sets are known as "false ribs" (costae spuriae), three of these sharing a common cartilaginous connection to the sternum, while the last two (eleventh and twelfth ribs) are termed floating ribs (costae fluctuantes) or vertebral ribs. They are attached to the vertebrae only, and not to the sternum or cartilage coming off of the sternum. Some people lack one of the two pairs of floating ribs, while others have a third pair.[citation needed]