The trachea extends from its attachment to the cricoid cartilage (C6) to the tracheal bifurcation at the carina (T5-6).

In adults it is 15 cm in length; 5 cm above the suprasternal notch, 8 cm if the neck is fully extended. The diameter of the trachea is approximately the same as the patient's index finger.

Patency is maintained by C-shaped cartilages anteriorly. The trachea is completed posteriorly by the trachealis muscle.

The trachea lies in the midline, anterior to the oesophagus, with the thyroid isthmus overlying the 2^nd to 4^th tracheal rings.

• Fig 1 highlights the surface anatomy of the trachea
• Fig 2 is a close-up of the trachea
• Fig 3 shows the carina