FACTS & HINTS

High-Yield Facts

Clinical Points

Recurrent laryngeal nerve injury

The recurrent laryngeal nerve supplies all of the intrinsic muscles of the larynxbut one.

Surgery, injury, or disease affecting the contents of superior mediastinum can damage either or both recurrent laryngeal nerves, reducing the voice to a hoarse whisper.

The left recurrent laryngeal nerve passes beneath the arch of the aorta and ascends to the neck between the trachea and the esophagus. Bronchogenic or esophageal carcinoma or an aneurysm of the arch of the aorta can thus affect this nerve.

Chylothorax

Surgical procedures involving the posterior mediastinum can injure the thoracic duct, which is hard to identifybecause it has a thin wall and is usuallycolorless.

Injuryto the thoracic duct can lead to leakage of lymph into the thoracic cavityat a volume of up to 200 mL per hour.

Lymph is called chyle when it is carrying chylomicrons (fat droplets) from the digestion of food in the gastrointestinal system.

If lymph from the thoracic duct enters the pleural cavity, the resulting condition is called a chylothoraxand mayrequire removal by thoracocentesis.

Mnemonics

Memory Aids

To remember the spinal nerve contributions to the phrenic nerve:C3,4,5 keeps the diaphragm alive

8-10-12: T8-Site at which inferior vena cava pierces the diaphragm

T10-Site at which esophagus pierces the diaphragm

T12-Site at which aorta pierces the diaphragm

Memory Aids

SAT (for major contents of the superior mediastinum): Superior vena cava, Arch of aorta, and Trachea

Turkeys Blow Eggs: Trachea lies Behind the Esophagus

page 122

page 123

Memory Aids

Relationship of Thoracic Duct to Esophagus and Azygos Vein

"The duck lies between two gooses." duck = thoracic duct

Two gooses = azyGOOSE and esophaGOOSE

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