AP BIOLOGY

Detailed explanation-1: -The pectoralis major is the superior most and largest muscle of the anterior chest wall. It is a thick, fan-shaped muscle that lies underneath the breast tissue and forms the anterior wall of the axilla.

Detailed explanation-2: -pectoralis muscle, any of the muscles that connect the front walls of the chest with the bones of the upper arm and shoulder. There are two such muscles on each side of the sternum (breastbone) in the human body: pectoralis major and pectoralis minor.

Detailed explanation-3: -The muscles discussed in this section include the fibers that make up the pectoral muscles: Pectoralis major. Pectoralis minor. Serratus anterior.

Detailed explanation-4: -The pectoralis major has a broad origin, based on which it is divided into three parts: clavicular part, sternocostal part and abdominal part. All three parts converge laterally and insert onto the greater tubercle of humerus.