Anatomy: Trachea

Chris van Zyl KHC

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Trachea: Landmarks

Begins at lower border of cricoid cartilage / C6

Extends to Carina Right of the midline Sternal angle T4 on inspiration / T6 on expiration

Lined by ciliated columnar epithelium 15 cm long / 2cm in diameter 15 – 20 incomplete rings of cartilage

Bridged post. by trachealis muscle

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Trachea

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Trachea

Variable shape Usually round, oval, 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.

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Trachea: Carina

Lies at T5 level T4 on expiration T6 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

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Relations: Cervical

Anterior: Isthmus anterior to

2nd, 3rd, 4th rings Inferior thyroid veins Strap muscles:

Sternohyoid, Sternothyroid

Posterior: Oesophagus, recurrent

laryngeal nerves Lateral:

Lobes of thyroid Common carotid artery

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Relations: Thoracic

Anterior: Brachiocephalic a. Left common carotid a. Left brachiocephalic v.

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Relations: Thoracic

Posterior: Oesophagus Left recurrent

laryngeal n.

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Relations: Thoracic

Left lateral: Arch of the aorta Left common carotid Left subclavian arteries

Right lateral: Right vagus nerve Arch of the azygos vein Pleura

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Blood supply

Upper trachea Inferior thyroid

artery Lower part

Branches of the bronchial artery

Venous drainage Inferior thyroid

venous plexus

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Right Paratracheal Stripe

Interface between trachea and right upper lobe Max normal thickness 4 mm

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Left Paratracheal Stripe

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

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Posterior Tracheal Stripe

Interface between trachea and right lung Normal max diameter 2.5 mm

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Tracheoesophageal Stripe

Interface between esophagus and trachea

Normal max diameter 5.5 mm

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References

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 McNicholas, Stephen

Eustace Third Edition