<prompt> Major blood supply of pectoralis major muscles isThoracoacromial trunkLateral thoracic aeryInternal mammary aery perforating branchesAxillary aery  <response>: Major blood Supply of Pectoralis major muscles is thoracoacromial trunk. The intercostal perforators arising from the internal mammary aery provide a segmental blood supply BD CHAURASIAS HUMAN ANATOMY.VOLUME 1. 6TH EDITION.PAGE NO 180. TABLE A1.5:aeries of upper limb 