Origin
Clavicular head – clavicle, medial aspect.
Sternocostal head – sternum, costal cartilages, external oblique aponeurosis.
Insertion
Humerus – bicipital groove.
Blood supply
Thoracoacromial artery, internal thoracic artery, superior thoracic artery, intercostal arteries.
Nerve supply
Medial pectoral nerve, lateral pectoral nerve.
Action
The pectoralis major has its primary action on the humerus bone – it is responsible for the flexion and rotation of the humerus and thus the arm.
Disease/Injury
Absence of pectoralis major on one side of the chest is known as ‘Poland syndrome.’
Muscle Exercise
The pectoralis muscles are one of the most important chest muscles for weightlifters and bodybuilders. Exercises such as pushups and bench presses increase the strength of the muscle.
Interesting facts
The pectorals are colloquially known as ‘pecs.’