The cervical spine is supported by a core of anterior and posterior paraspinous muscles. The aerodigestive passages comprise an anterior central visceral compartment directly in front of the vertebral column. The larynx and pharynx are suspended from the jaw and base of the skull, and the trachea and esophagus glide in and out of the superior thoracic aperture with swallowing and neck movement.
The carotid sheaths containing carotid artery, internal jugular vein and vagus nerve lie in the angle formed by the deep lateral neck muscles (scalenes) and the visceral compartment. The common carotid bifurcates at about the level of the tip of the hyoid cornu.
The cervical plexus and brachial plexus nerves emerge between the anterior and middle scalene muscles. The subclavian artery usually emerges through the same gap caudal to the brachial plexus. The phrenic nerve descends diagonally across the anterior scalene to enter the chest at the medial border of the first rib. The spinal accessory nerve descends to the trapezius across the posterior triangle of the neck.