Ribs and Sternum - Anatomy & Physiology
Costae
- Arranged in pairs and articulate with two successive vertebrae
- Bony dorsal part, body of rib, and ventral costal cartilage
- Increase in length, curvature and amount of cartilage craniocaudally
- Cartilage of last rib may fail to join that of its neighbor: said to be floating
- Join ventrally on the midline at the Sternum, which is comprised of three parts
- Manubrium: most cranial, projects beyond the first set of ribs and can be palpated
- Body: segmented sternebrae joined by cartilage in young animals that is later replaced by bone
- Xiphoid Cartilage: caudal end that projects between lower ends of costal arches, providing attachment for the linea alba
- Costal Joints:
- Costovertebral joint: head of rib articulates with vertebral column, ball and socket with very restricted mobility
- Costotransverse joint: tubercle articulates with vertebra, sliding joint
- Costosternal joints:
- Interchondral joints: asternal ribs, elastic syndesmoses
- Intersternal joints: impermanent synchondroses