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

Course of Posterior Intercostal Vessels

The posterior intercostal vessels are vital structures supplying the thoracic wall. These vessels include posterior intercostal arteries and veins that run along the intercostal spaces.

Origin of Posterior Intercostal Arteries

Most posterior intercostal arteries originate from the thoracic aorta, except for the upper intercostal arteries, which emerge from the superior intercostal artery.

Course and Distribution

Each posterior intercostal artery runs laterally from the thoracic aorta and travels between the internal intercostal muscle and the innermost intercostal muscle. It provides branches to adjacent tissues and anastomoses with anterior intercostal arteries.

Branches of Posterior Intercostal Arteries

• Dorsal branch – supplies spinal cord, vertebrae, and back muscles.
• Collateral branch – runs parallel and supplies intercostal muscles.
• Lateral cutaneous branch – provides blood supply to skin and subcutaneous tissue.

Posterior Intercostal Veins

The posterior intercostal veins accompany the arteries and drain into the azygos and hemiazygos venous systems.

Clinical Significance

Understanding the anatomy of posterior intercostal vessels is crucial for thoracic surgeries, vascular interventions, and clinical procedures such as thoracentesis.