biceps brachii

origin - long head supraglenoid tubercle of the scapula, short head - coracoid process of the scapula. innervation - musculocutaneous nerve. action - flexion and pronation (main supinator)

triceps brachii - 3 heads medial,lateral, long. the long head - origin - infraglenoid tubercle

brachialis

Deep muscles of the forearm