Scapula


 Scapula


          Scapula or shoulder blade is a triangular flat bone which is situated on the ribs from second to seventh on the posterior wall of chest and remains seprate by the muscles. In this way, the posterior portion of the petctoral girdle comes into existence. It has two surfaces costal and dorsal. There is a big pit on the costal surface which is called subscapular fossa. There is a bulgy ridge on the dorsal surface which is called spine. The clear ridge of spine separates suprasines fossa from the infraspines fossa. Spine and fossae provide space to the muscles which give movement to the arm. Spine comes to an end in the form of a big, flat acromon process. It makes acromiono clavicular joint by joining with clavicle and muscles of chest and arm attaché with it. There is a shallow pitunder the acronium which is called glenoid fossa; it works like a socket for the head of humerus. This joint makes the joint of shoulder or glenohumeral joint. Glenoid is a formation which is bulging out from the medial side of the upper end of fossa and it is called coracoid process whereby muscles of coracoclavakular ligament, arm and chest are connected of which there are movements in the joint.

     There are three border and two angles in the scapula. The medial border is parallel to vertebral column and there are superior and inferior angles on the ends of medial border. There is a lateral border from the upper side of the inferior angle to the glenoid fossa. Horizontally superior angle of glenoid fossa are called superior border.