are small muscles
placed between the transverse processes
of the vertebræ
In the cervical region they are best developed, consisting of rounded muscular and tendinous fasciculi
, and are placed in pairs, passing between the anterior and the posterior tubercles
respectively of the transverse processes of two contiguous vertebræ, and separated from one another by an anterior primary division of the cervical nerve
, which lies in the groove between them.
Both sets are supplied by the anterior divisions of the spinal nerves.
There are seven pairs of these muscles, the first pair being between the atlas and axis, and the last pair between the seventh cervical and first thoracic vertebræ.
In the thoracic region they are present between the transverse processes of the lower three thoracic vertebræ, and between the transverse processes of the last thoracic and the first lumbar
In the lumbar region they are arranged in pairs, on either side of the vertebral column,
The Intertransversarii laterales are supplied by the anterior divisions, and the Intertransversarii mediales by the posterior divisions of the spinal nerves.
The intertransversarii muscle is primarily innervated by anterior rami
of spinal nerves
, but partly also from posterior rami