Thyrocervical trunk

The thyrocervical trunk is a branch of the subclavian artery arising from the first portion of this vessel, i.e. between the origin of the subclavian artery and the inner border of the scalenus anterior muscle. It is located distally to the vertebral artery and proximally to the costocervical trunk.
Branches.
It is a short and thick vessel and it divides soon after its origin into four branches: 
The transverse cervical artery is present in about 1/3 of cases. In the rest, the dorsal scapular and superficial cervical arteries arise separately.
The suprascapular artery and transverse cervical artery both head laterally and cross in front of (anterior to) the scalenus anterior muscle and the phrenic nerve. The inferior thyroid artery runs superiorly from the thyrocervical trunk to the inferior portion of the thyroid gland.
These branches explain the alternative name for this blood vessel: the "truncus thyrobicervicoscapularis".