The costocervical trunk is a short arterial blood vessel located in the human shoulder. Arising from the subclavian artery, its branches supply the muscles of posterior region of the neck. It originates from the superior-posterior side of the subclavian beside and laterally to the thyrocervical trunk. From its site of origin, it passes backwards in the space between the scalene muscles. It has a very short course, having only 1 cm in length.
As it runs backwards, the costocervical trunk divides into two main branches: 1) the deep cervical artery (cervicalis profunda), which runs backwards and slightly upwards (in some individuals it arises straight from the subclavian); 2) the superior intercostal artery (also known as the highest intercostal), which has a descending course.
1) The deep cervical artery travels backwards under the neck of the first rib, ascending to the second cervical vertebra. Along its course, it supplies the deep muscles of the posterior part of neck, sending collateral branches to the spinal cord in the vertebral column, making their way through the intervertebral foramen to enter the canal between the seventh cervical and first thoracic. Its branches anastomose with those of the vertebral, ascending cervical, and occipital arteries.
2) The superior intercostal artery descends in front of the neck of the first and second rib. It gives off two posterior intercostal arteries that runs between the first and second intercostal spaces. These branches anastomoses with anterior intercostal arteries, which are offshoots of the internal thoracic artery. The superior intercostal artery also sends spinal and posterior branches that supply the muscles of the back.
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| Above, schematic picture showing the costocervical trunk as it arises from the subclavian artery. |