Answer to The Book Never Written by Dr. Seuss’ Arch Enemy
Correct answer is D. The mediastinum is divided into a superior and inferior mediastinum. The inferior mediastinum is further divided into an anterior, middle, and posterior. The borders of the anterior mediastinum are between the endothoracic fascia of the posterior aspect of the anterior thoracic wall and the pericardium. While this may seem a bit of a trivial point to a first year student, to a thoracic surgeon it is vital to know the boundaries. Piercing the pericardium is how one enters the pericardial cavity to either repair the heart, or worse-case-scenario, injure it.
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Answer to this question is based on material presented in lectures 13 of the Thorax Lecture Series.
= Superior mediastinum
= Involuted thymus in anterior mediastinum
= Superior mediastinum
= Pericardium
= Heart in pericardial cavity