True about pectoralis major muscle: (A) Abductor & Internal rotator of shoulder, (B) Blood supply by perforating branch of internal thoracic aery, (C) Blood supply by thoraco acromial aery, (D) Nerve supply by intercostal aery
Answer is C. 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-C7)Medial pectoral (C6-C8, T1)Action:-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 aery{Reference: Vishram Singh, pg no.40}