<prompt> True about pectoralis major muscleAbductor Internal rotator of shoulderBlood supply by perforating branch of internal thoracic aeryBlood supply by thoraco acromial aeryNerve supply by intercostal aery  <response>: PECTORALIS MAJOR:-Origin: Small clavicular head- medial half of anterior aspect of clavicle.Sternocostal head- lateral half of sternum upto 6th cailage., and medial pas of 2nd to 6th costal cailages.Inseion:-U shaped inseion into lateral lip of bicipital groove.Nerve supply:-Lateral pectoral C5-C7Medial pectoral C6-C8, T1Action:-Clavicular head- flexes arm Sternocostal head-adducts and medially rotates armOnly muscle of upper limb which is supplied by all 5 spinal segments that form brachial plexus.Blood supply:- pectoral branch of thoracoacromial aeryReference: Vishram Singh, pg no.40 