<prompt> All of the following structures forms the boundaries of the quadrangular space which is present under the deltoid muscle in the shoulder region, from the posterior side, EXCEPT:Teres minorTeres majorSurgical neck of humerusLong head of biceps brachii  <response>: Structures forming the boundaries of the quadrangular space from the posterior side are:Superiorly by teres minorInferiorly by teres majorLaterally by surgical neck of humerusMedially by long head of triceps brachiiContents of the quadrangular space are:Axillary nervePosterior circumflex humeral vesselsSagging pa of shoulder joint capsuleRef: Clinical Anatomy: a Problem Solving Approach By Kulkarni page 110. 