Ribs

The ribs or costae are numbered in sequence. In the Latin nomenclature, the Roman numerals costa I–XII. are used. In the Czech designation arabic numerals 1.–12. are used. We describe several parts on each rib: On the bony main part of the rib – os costae there are:
 * 1) caput costae – head of rib,
 * 2) collum costae – neck of rib,
 * 3) corpus costae – rib body,
 * 4) tuberculum costae – rib tubercle.
 * 1) sulcus costae – a shallow groove on the lower side,
 * 2) crista costae – lower edge of the rib,
 * 3) angulus costae – rib curvature.

Articular faces on the rib

 * Facies articularis capitis costae – is the articular surface on the head of the rib, for II.–IX. the rib is divided by crista capitis costae into two surfaces, because these ribs are connected to two adjacent vertebrae.
 * Facies articularis tuberculi costae – this surface on the tubercle of the rib connects to the transverse process of the vertebrae.
 * Free ends of costal cartilages – surfaces that connect the rib to the sternum or to the previous rib.

Types of ribs

 * Costae verae – are the true ribs, the first 7 pairs. These ribs are directly articulated anteriorly to the sternum by means of their cartilage.
 * Costae spuriae – are the false ribs, 8.–10.. These ribs are articulated by their cartilages with the cartilages of the previous ribs.
 * Costae fluctuantes – are the free ribs. It is the 11. and 12. pair. These ribs terminate freely in the muscles of the abdominal wall.

Shape differences of the ribs
Some ribs differ from the general shape.
 * Costa I. – on the first rib there is an imprint of the subclavian artery – sulcus arteriae subclaviae and roughness for muscle attachment – tuberculum musculi scaleni anterioris and roughness for musculus scalenus medius.
 * Costa II. – roughness for scalenus posterior muscle and tuberositas musculi serrati anterioris.
 * Costa XI. et XII. – they are slightly curved and lack a tuberculum.

Related articles

 * Bone