<prompt> In left subclavian artery, the branches of the first part of the subclavian artery are all EXCEPT:Vertebral arteryThyrocervical trunkInternal thoracic arteryCostocervical trunk  <response>: Costocervical trunk Ref: 173-74-BDC-3, 755-Snell 7thSUBCLAVIAN ARTERYRight subclavian arteryArise from brachiocephalic arteryLeft subclavian arteryArise from the arch of aortaThe subclavian artery is divided into three parts by the presence of the scalenus anterior muscle I. First part of the subclavian artervII. Second part of the subclavian artervBranchesBranches1. Vertebral artery2. Thyrocervical trunk-three branchesi Inferior thyroid arteryii Superficial cervicaliii Suprascapular arteries3. Internal thoracic artery Costocervical trunki Superior intercostals arteryii Deep cervical arteryIII. Third part of the subclavian artervExtend from the lateral border of the scaleneus anterior to the outer border of the first rib. Here, it becomes the axillary artery. 