Cervical trachea

The cervical trachea is a midline structure which passes inferiorly and slightly posteriorly from its junction with the inferior margin of the cricoid cartilage to its point of passage through the superior thoracic inlet. In the adult, the cervical portion is typically 5cm in length.

Superiorly, the layers of the inner tracheal wall are in continuity with the cricoid cartilage and are supported by an external cricotracheal ligament. Posteriorly and slightly to the left is the oesophagus; this relationship is maintained into the thorax. In the lateral grooves between oesophagus and trachea lie the recurrent laryngeal nerves. The carotid sheaths lie more laterally and extend to the posterolateral margins of the oesophagus.

The thyroid gland isthmus straddles the second to fourth rings of tracheal cartilage. The thyroid extends laterally to form two lobes; the superior margin of the lobes projects superolaterally over the lateral surfaces of superior trachea. The inferior margin of the thyroid lobes project inferolaterally over the lateral surfaces of the fifth to sixth tracheal cartilages.

Anteriorly in the inferior half of the cervical trachea are, from superficial to deep, the following structures:

• inferior thyroid veins
• laterally and to
  • the right: right common carotid artery and subclavian artery joining to form the right brachiocephalic trunk
  • the left: left common carotid artery
• on the right, right vagus running obliquely from lateral to the subclavian artery
• brachiocephalic veins passing medially
• pretracheal fascia

Anteriorly in addition, there may be the superior margin of an enlarged thymus and the thyroidea ima artery.