Lungs
Trachea
The trachea, aka your windpipe is a respiratory tubular structure which extends from C6 to T4/5. It is enforced by approximately 15 C-shaped hyaline cartilages. It is lined with ciliated pseudostratified columnar epithelium. The lining also has goblet cells which produces mucous.
At the tracheobronchial bifurcation, there is an anatomical landmark known as the carina, which is a ridge pointing superiorly on the inner surface. This is the most sensitive area to trigger a cough reflex.
The trachea is supplied by the tracheal branches of the inferior thyroid arteries.
Venous drainage is via the brachiocephalic, azygos and accessory hemiazygos veins.
It is innervated by both sympathetic and parasympathetic fibers. Pain sensation is governed by the sensory fibers of the vagus nerve (CN X) – recurrent laryngeal nerve.
The trachea is a median structure in the neck. Then it descends into the thoracic cavity anterior to the oesophagus and bifurcates in the superior mediastinum. This bifurcation deviates slightly to the left creating the left and right bronchus. The pathway downwards to the right bronchus is structurally more vertical and therefore is a common location for foreign body aspiration.
Tracheoesophaegeal Fistula
Tracheoesophageal fistula is a connection between the esophagus and the trachea. During embryonic development between week 4 – 8, the esophagus and trachea begin as a single tube that normally divides into the two adjacent passages. Tracheoesophageal fistula develops if this separation is disrupted.
Possible configurations include:
- oesophagus attaches to distal trachea (>80%)
- connections to the trachea from both the upper and lower sections of the esophagus
- the upper esophagus connected to the proximal trachea
- esophagus that is malformed but does not connect to the trachea
- a connection to the trachea from an otherwise normal esophagus.