Mellizmok

Mellizmok, in human anatomy, refer to the chest muscles, primarily the pectoralis major and the pectoralis minor. These muscles form part of the anterior chest wall and play important roles in moving the shoulder and stabilizing the scapula, as well as contributing to certain breathing actions during exertion.

The pectoralis major is a large, fan-shaped muscle that covers the upper chest. It has two main parts: the clavicular head, originating from the anterior surface of the clavicle, and the sternocostal head, originating from the sternum and the upper costal cartilages. Both heads converge to insert at the greater tubercle and the intertubercular groove of the humerus. Nerve supply comes from the lateral and medial pectoral nerves (C5–T1). Its arterial supply primarily comes from branches of the thoracoacromial trunk, with additional contributions from nearby vessels. The major actions of the pectoralis major include flexion, adduction, and internal rotation of the humerus, as well as horizontal adduction.

The pectoralis minor is a smaller, thinner muscle situated beneath the pectoralis major. It originates from the third to fifth ribs and inserts onto the coracoid process of the scapula. Its main function is to stabilize the scapula by drawing it anteriorly and inferiorly against the thoracic wall. It is innervated mainly by the medial pectoral nerve (with possible contributions from the lateral pectoral nerve) and receives blood supply from branches of the thoracoacromial trunk and surrounding perforating arteries.

Clinical relevance includes pectoral muscle strains or ruptures, especially of the pectoralis major in weightlifting. Tightness or dysfunction of the pectoralis minor can contribute to shoulder girdle issues such as impingement or thoracic outlet symptoms. Understanding mellizmok is essential for assessments in sports medicine, physical therapy, and related fields.