n :  a large flat triangular superficial muscle of each side of the upper back that arises from the occipital bone, the ligamentum nuchae, and the spinous processes of the last cervical and all the thoracic vertebrae, is inserted into the outer part of the clavicle, the acromion, and the spine of the scapula, and serves chiefly to rotate the scapula so as to present the glenoid cavity upward .
 
   
 
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