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
[{'content': 'In emergency tracheostomy the following structures are damaged except? \nSelect and explain. \nA. Isthmus of the thyroid, B. Inferior thyroid aery, C. Thyroid ima, D. Inferior thyroid vein', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 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)', 'role': 'assistant'}]