Pectoralis, also known as pectoralis major, is a noun that refers to a large, fan-shaped muscle located in the anterior part of the upper chest, specifically in the pectoral region. It is one of the major muscles in the upper body and is primarily responsible for movements of the shoulder joint, including flexion, adduction, and medial rotation.
The pectoralis muscle consists of two separate portions known as the clavicular and sternocostal heads, which originate from different points on the body. The clavicular head originates from the anterior surface of the medial half of the clavicle, while the sternocostal head arises from the anterior surface of the sternum, the superior six costal cartilages, and the aponeurosis of the external oblique muscle.
These two portions converge to form a thick, triangular muscle that inserts into the proximal humerus. The pectoralis muscle is attached to the humerus by a tendon, known as the pectoral tendon, which provides stability during movements of the arm and shoulder.
The pectoralis muscle plays a crucial role in upper body movements such as pushing, pulling, and lifting objects. It is actively engaged in exercises like bench presses, push-ups, and chest flys, and is a key muscle for athletes involved in sports such as weightlifting, bodybuilding, and swimming. In addition to its functional aspects, the pectoralis muscle also contributes to the aesthetic appearance of the chest, particularly in individuals with well-developed musculature.
