You are in the emergency room when a patient is brought in, the loser in a street fight. He has received a stab wound about 1.5 cm long in the right side of the chest about 1.5 cm below and 1 cm medial to the coracoid process of the scapula. He has lost a lot of bright red blood from a large (1.2 cm in diameter) severed artery found deep at this location. Intravenous fluids are immediately administered and a surgeon is called in to repair the artery. He begins by making an incision through the skin and subcutaneous tissue just below the clavicle, then cuts the clavicular head of the pectoralis major muscle and retracts it downward to obtain sufficient exposure of the area. He next encounters a partially severed muscle running downward and medially from the coracoid process. He divides the remaining fibers of the muscle and has you retract it downward. This exposes a bloody fat-filled space full of vessels and nerves. The muscle running downward and medially from the coracoid process which was partially severed was the