Costocervical trunk
Arises posteriorly and superiorly from the distal part of the subclavian artery.
Branches:
- Deep cervical artery
- Runs between the semispinalis capitis and semispinalis cervicis (more posteriorly and laterally than the ascending cervical artery) up to C2 level.
- Anastomoses with the vertebral artery and descending branches from the occipital artery
- Gives off branches supplying the cervical muscles
- May give off spinal branches usually at C7-T1 level
- Supreme intercostal artery
- Highest intercostal artery supplying the muscles, skin and adjacent pleura of the top 2-3 intercostal spaces
Anatomic variants
- The deep cervical artery may occasionally arise directly from the subclavian artery
- In about 25% of people there may be an accessory deep cervical artery
- The supreme intercostal artery may be absent, replaced by branches from the descending aorta, the inferior thyroid artery, second intercostal artery or the axillary artery