This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
In emergency tracheostomy the following structures are damaged except? 
Select and explain. 
A. Isthmus of the thyroid, B. Inferior thyroid aery, C. Thyroid ima, D. Inferior thyroid vein
B: Inferior thyroid aery
Answer: B: Inferior thyroid aery 
Explanation: Isthmus, thyroid ima aery and inferior thyroid veins are midline structures and thus can be injured during tracheostomy, more so during emergency tracheostomy. Inferior thyroid aery, a branch of the thyrocervical trunk of the subclan aery lies laterally away from midline, thus can escape injury. In emergency tracheostomy following structures can be damaged: - Isthmus - Inferior thyroid veins - Thyroid ima aery - Left brachio-cephalic vein, jugular venous arch - Pleura (especially infants) - Thymus - Esophagus (the trachea is small, mobile, and soft in infants damage the esophagus)