Origin, Course, and Branches of Anterior and Posterior Intercostal Vessels

Origin of Posterior Intercostal Vessels

The posterior intercostal vessels originate from the thoracic aorta and supply the intercostal spaces.

Arterial Supply

• First two posterior intercostal arteries arise from the superior intercostal artery.
• Remaining nine posterior intercostal arteries originate from the descending thoracic aorta.

Venous Drainage

• Posterior intercostal veins drain into the azygos and hemiazygos venous systems.
• Upper intercostal veins drain into the brachiocephalic veins.

Internal Thoracic Vessels

Internal thoracic vessels run parallel to the sternum, supplying anterior intercostal spaces and thoracic wall structures.

Branches

• Anterior intercostal arteries
• Pericardiophrenic artery
• Musculophrenic artery
• Superior epigastric artery