Ribs
The 12 pairs of ribs form the lateral thoracic cage, protecting thoracic organs and assisting respiration. They articulate posteriorly with thoracic vertebrae and most connect anteriorly to the sternum via costal cartilages.
Key Features
Articulations
- •Costovertebral joints (head with vertebral bodies) - synovial plane
- •Costotransverse joints (tubercle with transverse process) - synovial plane
- •Sternocostal joints (costal cartilage with sternum) - synovial (2-7) or synchondrosis (1st)
Muscle Attachments
Clinical Relevance
Rib fractures are common from trauma; first rib fractures indicate severe force. Flail chest occurs with multiple adjacent fractures. Intercostal nerve blocks relieve rib pain. Cervical ribs can cause thoracic outlet syndrome.
Ribs FAQs
Common questions about this bone
True ribs (1-7) attach directly to the sternum via their own costal cartilage. False ribs (8-10) attach to the cartilage of the rib above. Floating ribs (11-12) have no anterior attachment at all.
The costal groove is a groove on the inferior internal surface of each rib that protects the intercostal vein, artery, and nerve (in that order from superior to inferior: VAN).
Flail chest occurs when a segment of the chest wall moves independently due to multiple rib fractures in two or more places. The flail segment moves paradoxically (inward on inspiration), compromising breathing.
A cervical rib is an extra rib arising from the C7 vertebra, present in about 0.5% of people. It can compress the brachial plexus or subclavian vessels, causing thoracic outlet syndrome.