How long is the human trachea?

Trachea is a tube composed of cartilage and membrane tissue.

Connect the larynx and bronchus. Trachea is a continuation of larynx at cricoid cartilage level. The upper end of the trachea is at the level of the sixth or seventh cervical vertebra, and the lower end is at the level of the fourth or fifth thoracic vertebra. When inhaling deeply, the lower end of trachea can reach the level of the sixth thoracic vertebra. In a calm state, the length of adult trachea is10-1LCM, and it is about 5cm above the sternal notch.

The non-cartilaginous part between cartilaginous rings is elastic and can be extended or shortened with respiratory movement (or neck flexion and extension). Thoracic surgeons use this to deal with tracheotomy. After segmental tracheotomy, the neck can remain in flexion position, which can minimize the tension of tracheal anastomosis. The skin of mandible is often sutured with the skin in front of the sternal stalk to prevent the neck from overstretching after operation.

The bifurcation of trachea is also called carina, and its projection in front of the body surface is located in sternal angle, or the front end of the second costal cartilage. In children, the carina is located at the level of the third costal cartilage (Nagaishi,1972; Williams and Warwick, 198 1). The trachea is centered and slightly convex to the right.