Costocervical trunk

Arises posteriorly and superiorly from the distal part of the subclavian artery.

Branches:

1. 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

2. 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