In anatomy, the scapula (Medical Latin), or shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). The scapula forms the posterior (back) located part of the shoulder girdle. In humans, it is a flat bone, roughly triangular in shape, placed on a posterolateral aspect of the thoracic cage. There are three borders of the scapula: 1) The superior border is the shortest and thinnest; it is concave, and extends from the medial angle to the base of the coracoid process. It is referred to as the cranial border in animals. 2) The axillary border (or "lateral border") is the thickest of the three. It begins above at the lower margin of the glenoid cavity, and inclines obliquely downward and backward to the inferior angle. It is referred to as the caudal border in animals. 3) The vertebral border (or "medial border") is the longest of the three, and extends from the medial to the inferior angle. It is referred to as the dorsal border in animals. There are 3 angles: 1) The superior angle is covered by trapezius. 2) The inferior angle is covered by latissimus dorsi. It moves forwards round the chest when the arm is abducted. 3) The lateral or glenoid angle is broad and bears the glenoid cavity or fossa, which is directed forward, laterally and slightly upwards.