Intertransversarii muscle

The Intertransversarii are small muscles placed between the transverse processes of the vertebræ.

Cervical
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.


 * The muscles connecting the anterior tubercles are termed the Intertransversarii anteriores.
 * Those between the posterior tubercles are termed the Intertransversarii posteriores.

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.

Thoracic
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.

Lumbar
In the lumbar region they are arranged in pairs, on either side of the vertebral column,
 * one set occupying the entire interspace between the transverse processes of the lumbar vertebræ, the Intertransversarii laterales.
 * the other set, Intertransversarii mediales, passing from the accessory process of one vertebra to the mammillary of the vertebra below.

The Intertransversarii laterales are supplied by the anterior divisions, and the Intertransversarii mediales by the posterior divisions of the spinal nerves.

Innervation
The intertransversarii muscle is primarily innervated by anterior rami of spinal nerves, but partly also from posterior rami.