Upper limb
Internal thoracic artery (Internal mammary artery / LIMA)
Arteria thoracica interna
- Origin
- Arises from the inferior aspect of the first part of the subclavian artery
- Insertion
- Descends behind the costal cartilages approximately 1-2 cm lateral to the sternum, dividing into musculophrenic and superior epigastric arteries
- Function
- Supplies anterior chest wall, sternum, breast, pericardium, and anterior intercostal spaces
- Innervation
- Sympathetic vasomotor fibers
- Movement & chain
- Secured to the endothoracic fascia along the retrosternal chest wall
- Palpation
- Not palpable through anterior costal cartilages
- Clinical
- Gold standard bypass conduit (Left Internal Mammary Artery - LIMA) in coronary artery bypass grafting (CABG) due to exceptional long-term patency
- Segmental innervation
- C5–T1 roots (supplying T1–T6 anterior chest wall)
- In clinical practice
- Pivotal vessel in cardiac surgery; protected during parasternal sternotomy closure and intercostal nerve blocks
- Region in the model
- Upper limb