Anatomy Trachea Chris van Zyl KHC Trachea Landmarks

Anatomy: Trachea Chris van Zyl KHC

Trachea: Landmarks 2 Begins at lower border of cricoid cartilage / C 6 ¨ Extends to Carina ¨ ¤ Right of the midline ¤ Sternal angle ¤ T 4 on inspiration / T 6 on expiration Lined by ciliated columnar epithelium ¨ 15 cm long / 2 cm in diameter ¨ 15 – 20 incomplete rings of cartilage ¨ ¤ Bridged post. by trachealis muscle

Trachea 3

Trachea 4 ¨ Variable shape ¤ Usually round, oval with flattened post. border ¤ Square ¤ Inverted pear ¤ Horseshoe Very pliable in children ¨ May deviate to the right at almost 90° in normal expiratory film. ¨

Trachea: Carina 5 ¨ Lies at T 5 level ¤ T 4 on expiration ¤ T 6 on inspiration ¨ Normal angle: 65° ¤ 20° to right of midline ¤ 40° to left of midline Angle slightly larger + symmetrical in children ¨ Angle increases by 10° - 15° in recumbency ¨

Relations: Cervical 6 ¨ Anterior: ¤ ¤ ¤ ¨ Posterior: ¤ ¨ Isthmus anterior to 2 nd, 3 rd, 4 th rings Inferior thyroid veins Strap muscles: Sternohyoid, Sternothyroid Oesophagus, recurrent laryngeal nerves Lateral: ¤ ¤ Lobes of thyroid Common carotid artery

Relations: Thoracic 7 ¨ Anterior: ¤ Brachiocephalic a. ¤ Left common carotid a. ¤ Left brachiocephalic v.

Relations: Thoracic 8 ¨ Posterior: ¤ Oesophagus ¤ Left n. recurrent laryngeal

Relations: Thoracic 9 ¨ Left lateral: ¤ Arch of the aorta ¤ Left common carotid ¤ Left subclavian arteries ¨ Right lateral: ¤ Right vagus nerve ¤ Arch of the azygos vein ¤ Pleura

Blood supply 10 ¨ Upper trachea ¤ Inferior ¨ thyroid artery Lower part ¤ Branches of the bronchial artery ¨ Venous drainage ¤ Inferior thyroid venous plexus

Right Paratracheal Stripe 11 Interface between trachea and right upper lobe ¨ Max normal thickness 4 mm ¨

Left Paratracheal Stripe 12 Left upper lobe and trachea ¨ Less common (only on 21 %- 31% of films ¨

Posterior Tracheal Stripe 13 Interface between trachea and right lung ¨ Normal max diameter 2. 5 mm ¨

Tracheoesophageal Stripe 14 Interface between esophagus and trachea ¨ Normal max diameter 5. 5 mm ¨

References 15 ¨ Lines and Stripes: Where Did They Go? ¨ Jerry M. Gibbs, Chitra A. Chandrasekhar, Emma C. Furgasson, ¨ Sandra A. A. Oldham ¨ Applied Radiological Anatomy ¤ ¨ Paul Butler, Adam W. M. Mitchell, Harold Ellis Anatomy for Diagnostic Imaging ¨ Stephanie Ryan, Michelle Mc. Nicholas, Stephen Eustace ¨ Third Edition