The left recurrent laryngeal nerve recurs around the: (A) Left primary bronchus, (B) left subclan aery, (C) Left subclan vein, (D) Ductus aeriosus
Answer is D. Early in embryological development, both the right and left recurrent laryngeal nerves hook (recur) around aoic arch 6. The left aoic arch 6 persists as the ductus aeriosus(distal pa) while proximal pa of it forms pulmonary aery. 6TH phyrangeal arch derivatives:- Nerve-reccurent laryngeal nerve Aery- pulmonary aery (and ductus aeriosus) Muscles - all muscles of larynx except cricothyroid.