Semispinalis dorsi

The Semispinalis dorsi (or semispinalis thoracis) consists of thin, narrow, fleshy fasciculi, interposed between tendons of considerable length.

It arises by a series of small tendons from the transverse processes of the sixth to the tenth thoracic vertebræ, and is inserted, by tendons, into the spinous processes of the upper four thoracic and lower two cervical vertebrae.