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
Injury of which of these nerve cause vocal cord paralysis? 
Select and explain. 
A. Recurrent laryngeal, B. External laryngeal, C. Internal laryngeal, D. Superior laryngeal
A: Recurrent laryngeal
Answer: A: Recurrent laryngeal 
Explanation: When both recurrent laryngeal  nerves are interrupted,  the vocal cords lie in the cadaveric position in between abduction and adduction and phonation is completely lost. Deep breathing also becomes difficult through the partially opened glottis.
When only one recurrent laryngeal nerve is paralysed, the opposite vocal cord compensates for it and phonation is possible but there is hoarseness of voice.  There is failure of forceful explosive part of voluntary and reflex coughing.

BDC Head and Neck 6th Ed P:258