<prompt> Superior thoracic apeure is bounded by following exceptT1 veebra1st pair of ribs and their costal cailageSuperior border of the manubriumXiphoid process  <response>: Superior thoracic apeure is not bounded by Xiphoid process B D CHOURASIAS HUMAN ANATOMY UPPER LIMB THORAX VOLU, 1 SIXTH EDITION, PAGE NO, 190 