Rinnalihasarter

Rinnalihasarter, in Finnish, refers to the arteries that supply the chest muscles (rinnalihas), primarily the pectoralis major and pectoralis minor. The main arterial sources are the pectoral branch of the thoracoacromial trunk, the lateral thoracic artery, and perforating branches of the internal thoracic (internal mammary) artery. Additional supply comes from perforating branches of the intercostal arteries. The term is used in anatomical descriptions and in surgical contexts involving the chest wall and breast tissue.

Origin and course: The pectoral branch of the thoracoacromial trunk arises from the second part of the axillary artery and runs toward the pectoral muscles to supply pectoralis major and minor. The lateral thoracic artery, another axillary branch, descends along the lateral chest wall to nourish the pectoral muscles and contribute to breast vascularization. The internal thoracic artery travels along the inner chest wall and issues perforating branches that pass through the intercostal spaces to reach the pectoral muscles and overlying skin. Intercostal arteries also provide perforators to the anterior chest wall.

Variation and clinical relevance: Vascular patterns to the rinnalihas show considerable anatomical variation between individuals, with different contributions from the thoracoacromial trunk, lateral thoracic artery, and internal thoracic perforators. In chest-wall and breast surgery, knowledge of these vessels is important for preserving muscle and skin perfusion during procedures such as mastectomy, reconstruction, and flap surgery. Pedicled pectoralis major flaps commonly rely on arteries from the thoracoacromial trunk or the lateral thoracic artery.