Dorsal Branches of the Posterior Intercostal Arteries, Lateral View

Description

Running within each thoracic interspace, the posterior intercostal arteries course along the inferior margins of the ribs and give off dorsal branches that turn posteriorly toward the vertebral column in this left lateral male view. From their origin near the thoracic aorta, the dorsal branches pass medially and posteriorly, then track toward the paraspinal musculature adjacent to the spinous and transverse processes. Rib contours and intercostal spaces frame the arterial pathways, with the vertebral column forming the medial boundary of the field. Major cervicothoracic vessels and the humerus appear in profile as regional landmarks, but the emphasis stays on the segmental arterial pattern along the thoracic cage. Clinically, dorsal branches matter because they supply the deep back muscles, periosteum, and skin via posterior cutaneous branches, and they participate in collateral flow when proximal inflow is compromised. Their close relationship to the vertebral column and intercostal spaces also explains why segmental vessel control becomes relevant during posterior thoracic procedures, including costotransversectomy and posterior approaches for thoracic spine instrumentation. Small arteries, real consequences. Awareness of their course helps anticipate bleeding along the posterior rib angle and near the transverse processes, where vessels can be encountered when elevating muscle off bone. Anatomy faculty can use this plate to teach segmental vascular anatomy of the thoracic wall in gross anatomy, back and thorax labs, and surgical anatomy modules focused on posterolateral thoracic exposure. Medical publishers and clinical educators will also find it suitable for atlas content on posterior intercostal artery branching, collateral pathways, and procedural risk discussions in thoracic surgery, anesthesia, and spine surgery contexts. Anatomical accuracy verified by SciePro's Medical Advisory Board.