Expansion
Anterior intercostal, perforating and pericardiacophrenic branches, ending as superior epigastric and musculophrenic arteries
Expansion
Arising from the first part of the subclavian artery, it descends about a centimetre lateral to the sternal edge and gives:
- Anterior intercostal branches to the upper six spaces
- Perforating branches, which supply the breast
- Pericardiacophrenic branch, accompanying the phrenic nerve
- Mediastinal and thymic branches
At the sixth intercostal space it divides into its two terminal branches:
- Superior epigastric artery
- Musculophrenic artery
The perforating branches explain why the medial breast drains and bleeds towards the parasternal chain, and the superior epigastric continuation is the anastomosis that links thoracic and abdominal wall circulations.