Anomaly of tracheal cartilage (Q87434)

This refers to an anomaly of the cartilage in the trachea, which varies from sixteen to twenty in number. Each forms a semicircular ring of hyaline cartilage, which occupies the anterior two-thirds or so of the circumference of the trachea. The posterior one-third of the trachea is completed by fibrous tissue and smooth muscle fibres.