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In anatomy, the scapula (plural scapulae or scapulas)〔O.D.E. 2nd Ed. 2005〕 or shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones the scapulae are paired, with the scapula on the left side of the body being roughly a mirror image of the right scapula. In early Roman times, people thought the bone resembled a trowel, a small shovel. The shoulder blade is also called omo in Latin medical terminology. The scapula forms the back of the shoulder girdle. In humans, it is a flat bone, roughly triangular in shape, placed on a posterolateral aspect of the thoracic cage. == Structure == It is a wide, flat bone lying on the thoracic wall that provides an attachment for three different groups of muscles. The intrinsic muscles of the scapula include the muscles of the rotator cuff- the subscapularis, teres minor, supraspinatus, and infraspinatus.〔Marieb, E. (2005). Anatomy & Physiology (2nd ed.). San Francisco, CA: Pearson Benjamin Cummings.〕 These muscles attach to the surface of the scapula and are responsible for the internal and external rotation of the glenohumeral joint, along with humeral abduction. The extrinsic muscles include the biceps, triceps, and deltoid muscles and attach to the coracoid process and supraglenoid tubercle of the scapula, infraglenoid tubercle of the scapula, and spine of the scapula. These muscles are responsible for several actions of the glenohumeral joint. The third group, which is mainly responsible for stabilization and rotation of the scapula, consists of the trapezius, serratus anterior, levator scapulae, and rhomboid muscles and attach to the medial, superior, and inferior borders of the scapula. The head, processes, and the thickened parts of the bone, contain cancellous tissue; the rest consists of a thin layer of compact tissue. The central part of the supraspinatus fossa and the upper part of the infraspinatous fossa, but especially the former, are usually so thin in humans as to be semitransparent; occasionally the bone is found wanting in this situation, and the adjacent muscles are separated only by fibrous tissue. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Scapula」の詳細全文を読む スポンサード リンク
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