FACTS & HINTS
High-Yield Facts
Clinical Points
Recurrent laryngeal nerve injury
The recurrent laryngeal nerve supplies all of the intrinsic muscles of the larynx but 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 identify because it has a thin wall and
is usually colorless.
Injury to the thoracic duct can lead to leakage of lymph into the thoracic cavity at 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 chylothorax and may require 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