Question

The pectoral muscles have their origin in the _______________ and _______________, and insertion on the ______________________. Their main action is to ________________ and medially _________________ the arm.

Answer 1

The pectoral muscles have their origin in the clavicle(collar bone),Anterior surface of sternum and lower rib cartilage, and insertion on the bicipital groove of the humerus.Their main action is to flex the arm at the shoulder joint, extend the arm at the shoulder joint(glenohumeral) from a flexed position, and medially rotate the arm.

the muscles which is connect front walls of the chest, with the bones of the upper arm and shoulder called pectoralis major and pectoralis minor.

The pectoralis major- large mucule  origin from the clavicle,sternum, ribs. Major actions are adduction, or depression, of the arm and rotation of the arm forward about the axis of the body.