Trunk (thorax, abdomen, back)
Ribs and costal cartilages (I–XII)
Costae et cartilagines costales (I–XII)
- Origin
- Extend from thoracic vertebrae (T1–T12) posteriorly to the sternum anteriorly via costal cartilages
- Insertion
- Attachment site for intercostal muscles, serratus anterior, pectoralis minor, and diaphragm
- Function
- Enclose and protect thoracic organs (lungs, heart); expand thoracic cavity during respiration
- Innervation
- Intercostal nerves (T1–T12)
- Movement & chain
- Bucket-handle and pump-handle movements increasing transverse and anteroposterior thoracic dimensions
- Palpation
- Ribs and intercostal spaces are palpable across lateral and anterior chest wall
- Clinical
- Rib fractures (complications: pneumothorax, hemothorax); costochondritis (Tietze syndrome); flail chest
- Segmental innervation
- T1–T12
- In clinical practice
- Key landmarks for cardiac/pulmonary auscultation and chest tube insertion (5th ICS midaxillary line)
- Region in the model
- Trunk (thorax, abdomen, back)